Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	(introduction...)
	Preface
	1. Wood
		(introduction...)
		1.1. Structure of Wood
		1.2. Chemical Composition of Wood
			(introduction...)
			1.2.1. Cell Wall Components of Wood
			1.2.2. Wood Constituents
		1.3. Physical Properties of Wood
			(introduction...)
			1.3.1 Wood Density
			1.3.2. Moisture Content of Wood
			1.3.3. Swelling and Shrinking of Wood
			1.3.4. Thermal Properties of Wood
			1.3.5. Acoustic and Electric Properties of Wood
			1.3.6. Friction Properties of Wood
			1.3.7. Strength of Wood
		1.4. Important Wood Species
		1.5. Wood Defects Caused by Growth Influences
	2. Materials Made of Wood
		2.1. Solid Wood
			(introduction...)
			2.1.1. Not Improved Solid Wood
			2.1.2. Improved Solid Wood
		2.2. Laminated Wood
		2.3. Sandwich Boards
		2.4. Fibreboards
		2.5. Particle Boards
	3. Plastic materials
		(introduction...)
		3.1. Classification of Plastic Materials
		3.2. Properties of Important Plastic Materials
		3.3. Applications of Important Plastic Materials
	4. Glass Materials
		(introduction...)
		4.1. Classification of Glass Materials
		4.2. Properties of Glass Materials
		4.3. Applications of Glass Materials
	5. Steel
		(introduction...)
		5.1. Classification of Steels
		5.2. Properties of Important Steels
		5.3. Applications of Important Steels
		5.4. Screws and Nails
	6. Basic Terms of Cutting
		(introduction...)
		6.1. Faces and Angles on the Tool
		6.2. Directions of Cutting
		6.3. Cutting Speeds
		6.4. Cutting-Edge Dulling and Cutting-Edge Wear
	7. Hand Tools
		(introduction...)
		7.1. Measuring and Marking Tools
		7.2. Sawing Tools
		7.3. Planing Tools
		7.4. Mortising and Ripping Tools
		7.5. Drilling and Boring Tools
		7.6. Rasps and Files
		7.7. Other Tools
	8. Wood Working Machines
		8.1. Sawing Machines
			(introduction...)
			8.1.1. Circular Saw Benches
			8.1.2. Parallel Rocking Circular Sawing Machine
			8.1.3. Table Band Sawing Machine
		8.2. Milling Machines
			(introduction...)
			8.2.1. Smooth Miller
			8.2.2. Thicknessing Miller
			8.2.3. Shaping Machine
			8.2.4. Slot Milling Machine
		8.3. Lathe
		8.4. Drilling Machines
			(introduction...)
			8.4.1. Box-Column Drilling Machine
			8.4.2. Hand Drilling Machine
		8.5. Sanding Machines
			(introduction...)
			8.5.1. Horizontal Belt Sanding Machine
			8.5.2. Column-Type Disk Sanding Machine
		8.6. Presses
		8.7. Sharpening Machines
			8.7.1. Ripping Chisel and Plate Iron Sharpening Machine
			8.7.2 Sharpening Machine for Circular and Band Saw Blades
			8.7.3 Milling Cutter Sharpening Machine
			8.7.4. Blade Sharpening Machine
	9. Tools
		(introduction...)
		9.1. Tools for Circular Sawing Machines
		9.2. Tools for Table Band Sawing Machines
		9.3. Tools for Smooth and Thicknessing Millers
		9.4. Tools for Shaping Machines
		9.5. Tools for Slot Milling Machines
		9.6. Tools for Drilling Machines
		9.7. Tools for Sanding Machines
		9.8. Tools for Sharpening Machines
	10. Setting-up of Tools
		10.1. Setting-up of Hand Tools
		10.2. Setting-up of Machine Tools
	11. Gluing of Wood
		(introduction...)
		11.1. Important Terms of the Gluing Techniques
		11.2. Kinds, Properties and Processing of Important Glues
		11.3. Gluing Mistakes and Their Causes
	12. Surface Treatment of Wood
		(introduction...)
		12.1. Substances for Surface Treatment
		12.2. Use of the Coating Compositions
		12.3. Examples of Wood Coating Systems
	List of Symbols Used

		Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
			(introduction...)
			Preface
			1. Wood
			2. Materials Made of Wood
			3. Plastic materials
			4. Glass Materials
			5. Steel
			6. Basic Terms of Cutting
			7. Hand Tools
			8. Wood Working Machines
			9. Tools
			10. Setting-up of Tools
			11. Gluing of Wood
			12. Surface Treatment of Wood
			List of Symbols Used

Institut f�r berufliche Entwicklung e.V.
Berlin

Original title:
“Formeln und Tabellen - Holz”

Author: Dieter Zemmrich

First edition © IBE

Institut f�r berufliche Entwicklung e.V.
Parkstra�e 23
13187 Berlin

Order-No.: 93-34-0301/2

		Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
			(introduction...)
			Preface
			1. Wood
			2. Materials Made of Wood
			3. Plastic materials
			4. Glass Materials
			5. Steel
			6. Basic Terms of Cutting
			7. Hand Tools
			8. Wood Working Machines
			9. Tools
			10. Setting-up of Tools
			11. Gluing of Wood
			12. Surface Treatment of Wood
			List of Symbols Used

Preface

This training booklet was drawn up on the basis of wide experience gained in the field of vocational training in Germany. It is intended for trainees in woodworking and can well be used in theoretical and practical training.

In dealing with this subject, the main emphasis was put on describing the facts, the influencing factors and the possible application.

The list of the symbols used which is added will make quick and comprensive information possible.

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	1. Wood
		(introduction...)
		1.1. Structure of Wood
		1.2. Chemical Composition of Wood
			(introduction...)
			1.2.1. Cell Wall Components of Wood
			1.2.2. Wood Constituents
		1.3. Physical Properties of Wood
			(introduction...)
			1.3.1 Wood Density
			1.3.2. Moisture Content of Wood
			1.3.3. Swelling and Shrinking of Wood
			1.3.4. Thermal Properties of Wood
			1.3.5. Acoustic and Electric Properties of Wood
			1.3.6. Friction Properties of Wood
			1.3.7. Strength of Wood
		1.4. Important Wood Species
		1.5. Wood Defects Caused by Growth Influences

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

1. Wood

Wood is a tissue which is formed under the bark of the trunk by the meristem, the cambium. It consists of different cells.

1.1. Structure of Wood

The structure of the wood can be seen with the naked eye on the cut surfaces (see Fig. 1).

Figure 1 Sectional view

Fine Structure of Wood

The fine structure of wood is visible only under the microscope.

Tissue	Types of cells		Structure	Function	Occurrence
conducting tissue	tracheas		cells of different size and structure which are united into tubes; inside width: 0.02 - 0.5 mm length: a few cm to several m	water and nutrient conduction	deciduous wood
	tracheids		similar to the tracheas, but universally closed and dotted; inside width: 0.001 - 0.4 mm length: 0.3 -11 mm	water and nutrient conduction	all wood species
strengthening tissue and storage tissue	sclerenchymas		thick-walled, air-filled structures of small cross-section	strengthening of the wood	deciduous wood
storage tissue	parenchymas		mostly tape-shaped cells	metabolism and	all wood
		- axial parenchymas	strung together	storage of reserve substances	species
		- cross parenchymas	mostly square cells; containing many dots	nutrient storage and conduction in radial direction	all wood species
			longitudinal and cross parenchymae mostly form a multiple-branched network

1.2. Chemical Composition of Wood

Wood is composed of many chemical substances. The wood properties are considerably influenced by the composition.

Percentage in dry substance of wood

Carbon (C)	Oxygen (O)	Hydrogen (H)	Nitrogen (N)	Mineral substances
48...51	43...46	5...6	0.04...0.26	0.1...1.2

The percentages vary with the wood species.

1.2.1. Cell Wall Components of Wood

Percentage in dry substance of wood

Cellulose	Pantosanes	Lignin	Constituents
25...62	15.27	25...45	approx. 1.0
Composition of the cell components
44.4 % C	45.4 % C	62...69 % C	see under 1.2.2.
49.4 % O	49.4 % O	26...33.5 % O
6.2 % H	5.2 % H	6... 6.5 % H

1.2.2. Wood Constituents

Constituent	Description of the substance	Percentage in dry substance of wood	Importance of the constituent
alkaloids	metabolic product		protection against animal pests of wood
inorganic acid and salts	products of deposition		makes woodworking possibly more difficult
bitter substances	metabolic products
protein	ditto
colouring substances	excretion products of the cells or constituent of the cell sap
fats	reserve substances	up to 0.12...1.3 %
tannin	product of deposition	up to 17 %	protection against pests of wood, tannin extract recovery
glucosides	reserve substance
gum	protective substance		use for colouring and adhesive substances
resins	metabolic product		makes woodworking more difficult, serves for the manufacture of lacquers and adhesive substances
camphor	protective substance	up to 3 % and 1.5 % camphor oil	as distillation product for the recovery of essential oils
mineral substances	product of deposition		makes woodworking more difficult
oils	decomposition products	up to 1.6 %	protective agent
organic acids and salts	metabolic products		makes woodworking more difficult
odoriferous, toxic and curative substances	protective substance for the wood		may result in damage to the health during woodworking (see 1.4. under the various wood species)
starch	reserve substance	0.27...7.0 % sago palm up to 400 kg/tree	for food production and for gluten, thickeners and others
waxes	excretion products of the cell walls and the protoplasma	occurs seldom	makes surfaces treatment of the wood more difficult
sugar	conversion product of the starch	up to 3.5 % in the sap of Norway and sugar maple	saccharification of wood

1.3. Physical Properties of Wood

The physical properties of wood depend on the chemical composition and the biological structure.

1.3.1 Wood Density

The wood density is the ratio of the wood mass to the wood volume at a certain moisture content.

Designation	Definition	Calculation
density r	ratio of mass to volume of a substance	m = mass in g V = volume in cm
oven-dry density r_o	density of absolutely dry wood	m_o = mass in g at a moisture content of 0 % V_o = volume in cm³ at a moisture content of 0 %
gross density r_u the following are usual:	density of wood at a specific moisture content	m_u = mass in g at a specific moisture V_u = volume in cm³ at a specific moisture content
r 12...15 (12...15 % moisture content of wood) and r green (freshly felled timber)

Ratio of moisture content of wood to gross density (see Fig. 2).

Figure 2 Plot of gross density and moisture content

1.3.2. Moisture Content of Wood

The moisture of wood is the liquid content of wood.

Designation	Definition	Calculation
moisture content of wood u	water content of wood in % or in kg of water per kg of wood
oven-dryness	wood in absolutely dry condition
air-dryness	wood in air-dried condition (moisture content of wood 12 to 15 %)	u = moisture content of wood in % or in kg ^· kg^-1 m_u = mass of the damp wood sample in kg m_o = mass of the oven-dry wood sample in kg
fibre saturation	cell walls completely saturated with water (moisture content of wood 22 ... 36 % depending on the wood species)
water saturation	all voids filled with water (maximum moisture content)

1.3.3. Swelling and Shrinking of Wood

Swelling and shrinking is the change of dimensions of wood as a result of moisture take-up by the incorporation of water into cell wall or by the extraction of water from the cell wall.

Behavior of the wood	Definition	Amount of the change in dimension	Schematic Representation
longitudinal swelling a₁ and longitudinal shrinkage b₁	change in dimension of the wood in grain direction as a result of take-up or liberation of water	0.05...0.07 %
radial swelling a_r and radial shrinkage b_r	change in dimension of the wood vertically to the annual rings as a result of take-up or liberation of water	1.2...8.5 %
tangential swelling a_r and tangential shrinkage b_t	change in dimension of the wood in the direction of a tangent to the annual rings as a result of take-up or liberation of water	3.0...16.0 %

1.3.4. Thermal Properties of Wood

Wood has good heat-insulating properties, but is a bad heat conductor.

Quantity	Definition	Amount	Remarks
heat transfer coefficient a in kJ m^-2 h^-1 K^-1	amount of heat which within a certain period of time is transferred at an interface from one material to another	for wood in calm air a = 20...32, in a breeze of 1...5 m s^-1 a = 32...80
thermal resistance h in m² h K kJ^-1	resistance of a material to the heat transfer	d = wood thickness in mm l = coefficient of thermal conductivity in kJ m^-1 h^-1 k^-1
flash point t_F in ºC	temperature at which the wood starts to bum upon ignition	t_F for wood 200...275 ºC
calorific value H in kJ kg^-1	quantity of heat released during burning	calorific value for wood at u_o H » 19000 kJ kg^-1 at u = 12 % H » 13500 to 17000 kJ kg^-1	H is increasing with the content of carbon, hydrogen, combustible constituents, lignin and with rising density

1.3.5. Acoustic and Electric Properties of Wood

The acoustic properties of wood result from its ability to vibrate.

The electric properties are based on the fact that wood acts as an insulator when oven-dry.

Quantity	Definition	Amount	Remarks
sound velocity C in m s^-1	velocity at which sound waves propagate in a body	in grain direction 3000...5000 ms^-1	the ratio of the sound velocity in wood in grain direction to that across the grain is 1.3...1.5
sound damping b in phones or decibels; sound absorption S in %	assimilation of sound energy by the body exposed to sound waves; ratio of the sound energy absorbed by a body to the sound energy arrived at the body	k_s = absorbed sound energy k_a = sound energy arrived
specific electrical resistance r in W cm	electrical resistance of a cube with an edge length of 1 m		is getting smaller with increasing density and moisture

Sound absorption S of some sound-absorbing materials in % at a frequency of 512 Hz

Material	Thickness in mm	Application	S in %
wood-wool boards	25	directly on the wall	35
wood particle boards	13	at a distance of 50 mm to the wall, surface untreated	19
felt	5	directly on the wall	18

1.3.6. Friction Properties of Wood

Friction is defined as the action of forces which at two contacting surfaces resist motion.

Quantity	Definition	Amount resp. Calculation
force of static friction F_Rmax in kp	force necessary to make two surfaces slide against each other	F_rmax = f₀ *F_N f_o = coefficient of static friction F_N = normal force f_o _\|\| » 0.6 f_o ^ » 0.55
force of sliding friction F_R in kp	force to overcome the resistance to motion when one surface is moving on other surface	F_R = f * F_N f = coefficient of sliding friction f _\|\| » 0.5 f ^ » 0.35
force of rolling friction F_Rmin in kp	force to overcome the resistance which counteracts the rolling off of a cylinder	F = force acting in the centre of the circle r = radius of the circle

1.3.7. Strength of Wood

Strength is defined as the resistance of a body put up to the indentation by another object.

Quantity Schematic representation	Definition	Amount
hardness H in MPa	resistance of a body to the action of external forces
compressive strength d dB in MPa	resistance of a body to a compressive force acting from outside	F_max = compressive force A_o = cross-section
tensile strength d zB in MPa	maximum resistance of a body to tensile stress	F_max = tensile force A_o = cross-section
bending strength 6 dB in MPa	maximum load occurring under a bending stress	M_bmax = bending moment W = moment of resistance
shear strength t aB in MPa	resistance to destruction by shearing forces	F_max = shearing force A_o = shear surface
torsional strength t tB in MPa	highest tension occurring under torsional stress	Mt = torque a = length of a side of the cross-section

The torsional strength increases with density and with rising latewood and heartwood percentage and with decreasing moisture content.

Brinell hardness species in MPa of various wood			Mean shear strength of species in MPa various wood
Wood species	HB_\|\|	HB^	Wood species	t aB
Albura	48	28	Albura	7.6
Ail�	37	17	Ail�	7.0
B�t�	85	33	B�t�	8.0
Boss�	58	25	Boss�	10.6
Iroko	60	33	Ioroko	11.0
Tali	85	55	Tali	9.0

Calculation:

1.4. Important Wood Species

Trade name		Other names	Occurrence	Wood colour
				Heartwood	Sapwood
Abura		Bahia, Elilom, Subaha, Vuku	West and East Africa	greyish brown, brown to grey	yellowish red
African Mahogany		Khaya, Ndola, N’Gollom, Acajou d’Afrique	West Africa	light red, quickly darkening	light reddish grey
African Padouk		Barwood, Ndimbo, Epion, Takula, Ebeu	West Africa	coral-red, to reddish brown, darkening	whitish to cream-coloured
Aiel�		Atu�, Elimi, Abeui, M’bili, Bidinkala	West Central and East Africa	yellowish grey, yellowish brown	yellowish white to pale pink
Avodir�		Apaya, Engan, Agb�, Lusamba	tropic West Africa	pale yellow to cream-yellow, darkening
B�t�		Aprono, Ofun, Mansonia	West Africa	brownish to olive, often darkening	whitish
Bilinga		Aloma, Badi, Kusia, Opepe, Akondoc	West and East Africa	salmon-coloured, rose-pink, darkening	pale pink
Bintangor		Koila, Calophyllum	South-East Asia	reddish brown	yellowish grey
Boss�		Divuiti, Ibotou, Ebang-bemva, Akuraten	West Africa	salmon-coloured, rose-pink, darkening	pale pink
Bubinga		Oveng, Okweni, Kevazingo, Essingang	West Africa	reddish brown to purple red veined	greyish white to pale yellow
Dab�ma	Agboin, Atui, Toum, Dahoma, Bokundu		West and East Africa	yellowish brown to greyish brown		whitish grey to light brown
Dark red meranti	Adamui, Tanguile Nemesu, Meranti merah		South-East Asia	reddish brown		yellowish grey
Dib�tou	Apop, Bibolo, Bombolu, Alop		tropic West Africa	light to dark brown darkening		pale yellow to pale brown
Douka	Okola, Bavili, N’duka		West Africa	light red to reddish brown		reddish white
Doussi�	Afzelia, Bolengu, Papao, Uvala, M’bango		West and East Africa	light brown, often dark-veined		whitish to light yellow
Ebiara	Abem, Berlinia, Melegba, Obolo, Ekpogoi		West Africa	light reddish brown to reddish brown		yellowish white to reddish grey
Framir�	Lidia, Idigbo, Black afara		West Africa	greenish yellow, darkening		yellowish
Ilomba	Akomu, Lolako, Otie, Wal�l�		tropic West, Central and East Africa	pink to yellowish brown
Iroko	Abang, Odum, Kambala		West, Central and East Africa	greyish yellow to light brown, darkening		yellowish white to grey
Kosipo	Omu, Penkawa, Mpempe, Atomassi�		West and Central Africa	reddish brown		grey
Krabak	Sanai, Ven ven, bac, Palosapis		South-East Asia	yellowish to yellowish brown, darkening		pale yellow
Limba	Afara, Akom, Frak�, Ofram		West and Central Africa	pale yellow with a touch of olive, also greenish grey
Makor�	Baku, Aganope, Butusu		West Africa	pink to reddish brown, darkening		cream-coloured to reddish darkening
Merawan	Thong, Koki, Thingan, Kien kien		South-East Asia	yellowish, quickly darkening		pale yellow
Moabi	Njabi, Adza, Dimpampi		West Africa	dark red to reddish brown, darkening		light pink to dark grey
Movingui	Eyen, Barr� Ayan Bonsamdua		West Africa	lemon yellow to greenish yellow, darkening		yellowish grey
Mukulungu	Elang, Anzala, Fino, Autracon		West Africa	reddish brown, often dark-veined		yellowish grey to greyish brown
Naga	Okwen, Tebako, Meblo		West Africa	copper-coloured to reddish brown, light and dark stripes		light brown
Niangon	Ogou�, Kekosi, Yawi, Wishmore		West Africa	light to dark reddish brown, orange tinted		whitish to reddish grey
Okoum�	Caboon, Zonga, Angouma		West Africa	pale pink to reddish brown		light grey
East Indian jacaranda	East Indian rosewood, Sono keling, Eravadi		South Asia East India	yellowish brown to purple brown, darkening		yellowish
Ozigo	Assia		West Africa	grey yellowish to pale pink		pale grey, yellowish or reddish tinted
Sapelli	Lifaki, Sapele, Dilolo, Aboudikro		West, Central and East Africa	pale pink to light brown, darkening		cream-coloured, darkening
Sipo	Assi�, Utile, Timbi, Ogipopo		West, Central and East Africa	reddish brown, darkening		reddish grey to light brown
Tali	Alui, Eloun, Erum, Kassa, Muave		West, Central and East Africa	yellowish to reddish brown, veined		greyish white to yellowish
Teak	Kyun, Giathi, Tek Sak		South and South-East Asia	golden to yellowish brown, partly veined		whitish to grey l
Tiama	Edinam, Kalungi, Timbi, Gedu nohor		West and Central Africa	light red to reddish brown, darkening		whitish to reddish grey
Weng�	Awong, Mboto, Nson-so		West Africa	light brown, veined, darkening		whitish to greyish white
Yang	Dau, Gurjun, Keruing, Dzao long		South and South-East Asia	greyish pink to reddish brown		greyish red
Zingana	Amouk, Zebrano, Izingana		West Africa	light brown to greyish brown, veined		whitish to grey

Trade name	Gross density r 12...15 in g · cm^-3	Compressive strength d dB in MPa	Bending strength d bB in MPa	Tensile strength d zB in MPa
Abura	0.45 to 0.64	32...53	56...95	d zB^ 1.7...3.0
African Mahonany	0.45 to 0.62	36...58	36...126	d zB \|\| 33...101 d zB ^ 1.7...2.3
African Padouk	0.65 to 0.85	65...81	110...149	d zB ^ 1.9...5.7
Ail�	0.36 to 0.57	33...49	27. ..84	d zB \|\| 21...72 d zB ^ 1.6...2.6
Avodir�	0.50 to 0.60	40...57	52...113	d zB \|\| 84...113 d zB ^ 2.1....2.9
B�t�	0.58 to 0.68	48...97	62...187	d zB \|\| 52...173 d zB ^ 4.5...7.4
Bilinga	0.70 to 0.90	47...73	85...130	d zB ^ » 2.2
Bintangor	0.48 to 0.66	43...60	48...107	d zB \|\| 34...140
Boss�	0.55 to 0.65	45...61	74...110	d zB \|\| 42...99 d zB ^ 2.0...2.4
Bubinga	0.80 to 0.95	65...76	125...160	d zB ^ 3.6...4.8
Dabema	0.65 to 0.80	47. ..75	75...125	d zB ^ 1.9...3.7
Dark red meranti	0.59 to 0.89	53...74	77...158	d zB \|\| 66...222 d zB ^ » 2.7
Dib�tou	0.43 to 0.65	33...47	56...89	d zB \|\| 15...99 d zB ^ 1.6...2.1
Douka	0.65 to 0.75	40...71	41...146	d zB \|\| 30...127 d zB ^ 1.9...2.3
Doussi�	0.70 to 0.90	65...79	90...120	d zB ^ 1.8...2.3
Ebiaia	0.60 to 0.80	42...60	83...110	d zB ^ 2.7...4.0
Framir�	0.45 to 0.60	35...53	37...115	d zB ^ 1.2...2.3
Ilomba	0.35 to 0.53	31...45	41...74	d zB \|\| 45...76 d zB ^ 1.7...2.9
Iroko	0.55 to 0.85	52...81	70...158	d zB \|\| 55...140 d zB ^ 2.1...3.0
Kosipo	0.59 to 0.65	49...63	88...121	d zB \|\| 32...155 d zB ^ 1.9...3.5
Krabak	0.64 to 0.69	40...69	72...132	d zB \|\| 72...83 d zB ^ 3.8...5.6
Limba	0.48 to 0.78	35...48	58..94	d zB \|\| 26...165 d zB ^ 1.5.-2.8
Makor�	0.53 to 0.72	40...71	41...146	d zB \|\| 30...127 d zB ^ 1.9...2.3
Merawan	0.63 to 0.86	46...65	120...130	d zB ^ 2.4...3.0
Moabi	0.73 to 0.90	57...86	130...180	d zB ^ 3.2...4.4
Movingui	0.65 to 0.90	54...71	66...155	d zB \|\| 27...96 d zB ^ 2.5...2.9
Mukulungu	0.78 to 1.04	73...107	100...178	d zB \|\| 100...166
Naga	0.53 to 0.73	43...64	100...150
Niangon	0.58 to 0.72	56...68	87...140	d zB ^ 1.09...2.7
Okoum�	0.37 to 0.56	33...66	27...107	d zB \|\| 23...125 d zB ^ 1.5...2.1
East Indian jacaranda	0.70 to 0.95	57...65	119...132	d zB ^ 3.4...6.5
Ozigo	0.50 to 0.75	58...71	110...130	d zB ^ 2.6...4.0
Sapelli	0.51 to 0.75	37...78	60...164	d zB \|\| 53...154 d zB ^ 2.2....2.9
Sipo	0.55 to 0.75	43...73	47...155	d zB \|\| 57...164 d zB ^ 2.0...2.6
Tali	0.85 to 1.07	75...86	120...150	d zB ^ 2.7...4.0
Teak	0.52 to 0.70	42...59	58...109	d zB \|\| 95...155 d zB ^ 2.3...5.4
Tiama	0.51 to 0.63	38...59	61...92	d zB ^ 1.6...2.6
Weng�	0.75 to 0.95	68...90	115...170	d zB ^ 2.5...2.8
Yang	0.70 to 0.90	64...79	98...127	d zB \|\| 97...127 d zB ^ 3.8...5.6
Zingana	0.70 to 0.85	35...66	84...120	d zB ^ 2.8...4.3

Trade name	General properties	Effects detrimental to health	Applications
Abura	moderately hard, well workable, well cleavable, can well be stained, dyed, varnished and impregnated; susceptible to wood pests, not weather-proof	causes occasionally dermatitis*)	for peeled veneers, doors, windows, interior work, for furniture and model making
African mahogany	well workable, can well be glued, stained and varnished, relatively resistant to wood pests, not weather-proof	causes dermatitis	for sliced veneers and peeled veneers, for furniture construction, interior work, for parquet, doors and windows
African Padouk	easily workable, can well be glued and especially well be varnished, resistant to wood pests and weather influence	causes dermatitis, grinding dust must well be sucked off	especially for sliced veneers, for building doors and windows, for parquet and furniture construction and interior work
Aiel�	well cuttable, can well be nailed, screwed, glued, but is difficult to cleave; can well be stained and varnished; susceptible to wood pests, not weather-proof		for sliced and peeled veneers, in model making, for panelling and for packing
Avodir�	well cuttable and cleavable, can well be nailed, screwed and glued as well as stained and varnished, hard to impregnate, susceptible to wood pests, especially to blue stain, not weather-proof	causes occasionally irritations of the mucosa	preferably for making sliced veneer, but also for parquet, panelling and in furniture construction
B�t�	well workable, tools quickly get dull, well cleavable, can be stained and varnished, susceptible to animal wood pests, resistant to plant wood pests, weather-proof	causes dermatitis and irritations of the mucosa, nausea, vertigo	especially for sliced veneer, for windows and doors, panelling, parquet, in furniture construction and interior work
Bilinga	well cuttable, tools quickly get dull, can well be glued, stained, but is difficult to varnish, resistant to wood pests and weather influences	wood dust causes dermatitis	for sliced veneers, for building windows and doors, furniture, panelling, parquet and for interior work
Bintangor	easily workable, tools quickly get dull, can well be nailed and screwed, hard to cleave, susceptible to wood pests, weather-proof	skin irritations and disturbances of the general state of health possible	for veneer and plywood production, for furniture construction, for panelling and parquet, in boat building
Boss�	well cuttable, tools quickly get dull, can well be glued and stained, but is difficult to varnish, resistant to wood pests and weather influences	wood dust causes dermatitis	for veneer production, in furniture production, for panelling and parquet, for building doors and windows
Bubinga	workable with difficulty, tools quickly get dull, hard to cleave, can well be glued, stained and varnished, resistant to wood pests and weather influences		for veneer production, for furniture construction, for parquet and panelling, in waggon and vehicle construction
Dab�ma	workable with difficulty, tools quickly get dull, tends to splintering, predrilling is suitable for nailing and screwing, can well be stained and varnished, resistant to wood pests and weather influences	causes occasionally irritations of the mucosa	for manufacture of veneers, in furniture construction, for parquet and panelling, for interior work
Dark red meranti	easily workable, tools quickly get dull, can well be nailed and screwed, hard to cleave, susceptible to wood pests, weather-proof		for manufacture of veneers and plywood for furniture, parquet, windows and doors, for interior work and for boat building and vehicle construction
Dib�tou	easily workable, predrilling required for nailing and screwing, can well be glued, stained and varnished, hard to impregnate, susceptible to wood pests, not weather-proof	causes occasionally dermatitis	for sliced veneer, for furniture construction, for panelling and parquet, for interior work, vehicle construction and boat building
Douka	well workable, predrilling required for nailing and screwing, can well be glued, stained and varnished, relatively resistant to wood pests and weather influences	causes dermatitis, irritations of the mucosa and conjunctiva	for manufacture of veneers, for windows and doors, interior work, for furniture, parquet, in ship building, waggon and vehicle construction
Doussi�	well workable, tools quickly get dull, cannot be stained, hard to varnish, resistant to wood pests and weather influences	exposure to dust may result in irritations of the mucosa	for peeled veneer, windows, doors, floor coverings, furniture, in ship building and bridge construction, especially for laboratory furniture and containers for chemicals
Ebiara	well workable, danger of discolouring, can well be stained and varnished and easily impregnated, susceptible to wood pests, not weather-proof		for manufacture of sliced veneer, for internal work, in furniture construction and manufacture or parquet
Framir�	well cuttable and cleavable, can well be nailed, screwed, glued, stained and varnished, relatively resistant to wood pests, not weather-proof		for veneer and plywood production, for furniture, panelling, parquet, for windows and doors, interior work
Ilomba	can well be planed, milled, drilled, cleft, nailed, screwed, glued, stained and varnished, susceptible to wood pests, not weather-proof		for crossband veneers, packing and interior work, not suitable as building timber
Iroko	well workable, tools quickly get dull, predrilling required for nailing and screwing, can be varnished after pretreatment, cannot be impregnated, resistant to wood pests, weather-proof	causes occasionally dermatitis and irritations of the mucosa	for veneer and plywood production, for furniture, panelling, parquet, for doors and windows, for ship building and waggon construction and timber-work
Kosipo	well workable, tools quickly get dull, predrilling required for nailing and screwing, can well be glued, stained and varnished, susceptible to animal wood pests, not weather-proof		for sliced and peeled veneers, for plywood production, for furniture panelling and parquet and interior work
Krabak	well workable, tools quickly get dull, can well be nailed and screwed, glued, stained and varnished, susceptible to wood pests, not weather-proof		for veneer and plywood production, for furniture, parquet and interior work
Limba	well workable, can well be glued, stained and varnished, susceptible to wood pests, weather-proof	prolonged inflammations caused by splinter injuries are possible	for veneer and plywood production, interior work, for doors and windows, parquet, panelling, for furniture and timber-work
Makor�	well workable, tools quickly get dull, predrilling required for nailing and screwing, can well be glued, stained and varnished, relatively resistant to wood pests and weather influences	causes dermatitis, mucositis and conjunctivitis	for veneers, in furniture construction, for panelling, parquet, windows and doors, interior work, in ship building and waggon construction
Merawan	workable with difficulty, tools quickly get dull, can well be glued, stained and varnished, insect-proof, weather-proof, relatively acid-proof, durable under water		for sliced and peeled veneers, interior work, for floor coverings, panellings, in vehicle construction and ship building
Moabi	well cuttable, tools quickly get dull, can well be glued, stained and varnished, relatively resistant to wood pests, weather-proof	causes irritations of the mucosa	for veneer and plywood production, for furniture, parquet, windows and doors, interior work, vehicle construction, boat building and bridge construction
Movingui	workable with difficulty, tools quickly get dull, predrilling required for nailing and screwing, hard to cleave and glue, can well be stained and varnished, difficult to impregnate	causes occasionally dermatitis	for sliced veneeers, furniture, interior work, parquet, waggon construction, ship building and wood gluing work, for laboratory furniture and containers for chemicals
Mukulungu	well workable, tools quickly get dull, predrilling required for nailing and screwing, splinters, gluing difficult, paint coats badly adhere, hard to impregnate, acid-proof, resistant to wood pests and weather influences	causes irritations of the mucosa	for veneers, furniture, parquet, windows and doors, for interior work, waggon, vehicle and bridge construction, as timber for hydraulic engineering
Naga	well workable, predrilling required for nailing and screwing, can well be glued, stained and varnished, heartwood can be impregnated, relatively resistant to wood pests		for veneer and plywood production, for furniture and interior work, for windows, doors and floor coverings
Niangon	well workable, cleavable with difficulty, predrilling required for nailing and screwing, pretreatment necessary before gluing and surface treatment, resistant to wood pests, weather-proof		for veneer production, for interior work, for parquet, windows, doors, in vehicle construction, hydraulic and bridge engineering and construction of wooden houses
Okoum�	well workable, tools quickly get dull, can well be glued, stained and varnished, relatively resistant to wood pests, not weather-proof, fairly durable under water		for peeled veneer an plywood production, for furniture construction and interior work, for packing, in car body and boat building
East Indian jacaranda	well workable, tools quickly get dull, cleavable with difficulty, predrilling required for nailing and screwing, can well be glued, stained and varnished, resistant to wood pests, weather-proof	causes dermatitis	for sliced veneer production, for furniture, panelling, parquet, in model making and boat building
Ozigo	well workable, tools quickly get dull, can well be glued, stained and varnished, relatively resistant to wood pests, not weather-proof		for peeled veneer production, furniture construction, interior work, for parquet and packings
Sapelli	well workable, can well be glued, stained and varnished, relatively resistant to wood pests, not weather-proof		for sliced veneers, in furniture construction, for windows, doors, parquet, in vehicle construction and boat building
Sipo	well workable, can well be glued, stained and varnished, relatively resistant to wood pests, weatherproof		for veneer and plywood production, in furniture construction and interior work, for parquet, windows and doors, in vehicle construction and boat building
Tali	workable with difficulty, hard to cleave, tools quickly get dull, predrilling required for nailing and screwing, difficult to glue, can well be stained and varnished, resistant to wood pests, weatherproof	causes irritations of the mucosa	for veneer production, for parquet, windows, doors, floor coverings, in vehicle construction, bridge construction and mining, for containers for chemicals
Teak	well workable, predrilling required for nailing and screwing, tools quickly get dull, gluing and varnishing difficult, resistant to wood pests, weather-proof, acid-proof, inflammable with difficulty	causes occasionally dermatitis	for sliced veneers, in furniture construction, for parquet, windows, doors, for interior work, in vehicle construction and boat building, in hydraulic engineering, for containers for chemicals
Tiama	well workable, resin content causes clogging of the tools, can well be glued, stained and varnished, resistant to vegetable wood pests, but suscectible to animal wood pests, not weather-proof		for veneer and plywood production, for furniture, interior work, for parquet, windows, doors, in vehicle construction and boat building
Weng�	well workable, predrilling required for nailing and screwing, gluing and surface treatment difficult, resistant to wood pests, weather-proof		for sliced veneers, for furniture, panellings, parquet, windows and doors, as structural timber in the building industry
Yang	workable with difficulty, tools quickly get dull, resin content causes clogging of the tools, hard to glue, surface treatment difficult, relatively resistant to wood pests, moderately weather-proof	causes dermatitis, irritations of the mucosa furunculosis	for veneer and plywood production, for windows and doors, for interior work, vehicle construction and ship building
Zingana	moderately well workable, cleavable with difficulty, can well be glued, stained and varnished, resistant to wood pests and weather influences		for sliced veneers, in furniture construction, for interior furnishing, for windows and doors

*) dermatitis - inflammation of the skin caused by external influences

1.5. Wood Defects Caused by Growth Influences

Defects of and damage to the wood are deviations from the normal quality.

Kind of defect		Description of defect	Consequences	Wood species concerned
taper		reduction of the trunk diameter by 1 cm · m^-1	lower wood yield	Douka, Yang
curvature		curved deviation of the trunk from the straight line	lower wood yield, warping, shakes	wood species mentioned under 1.4.
wavy rings	deviation from the normal trunk cross-section by pointed or round wave-shaped annual rings		limited use, lower wood yield, strength variations, warping, shakes	African Padouk, Avodir�, Tali
eccentric growth, heart displacement	deviations of the pith duct from the centre of the cross-section visible in the cross-section		limited use, lower wood yield, strength variations, warping, shakes	African mahogany, Ail�, Avodir�, B�t�, Dark red meranti, Dibetou, Douka, Ebiara, Framir�, Ilomba, Kosipo, Limba, Krabak, Moabi, Mukulungu, Niangon, Okoum�, Ozigo Tali, Teak
spiral growth	helical wood fibre direction around the trunk axis		limited use, lower strength, shakes, warping	Abura
tension wood	wood zones on the upper side of crooked trunks and branches which appear to be of lighter colour than the surrounding wood		greater swelling and shrinkage, due to warping, shakes, working is more difficult	Doussi�
ring shakes	circular shakes following the annual rings mainly in the lower part of the trunk		unusable as timber	African Padouk, Framier�
knottiness	excessive existence of a great number of knots, in particular also dry, dead knots		lower wood yield, lower quality of the timber, reduced strength	Abura, Avodir�, B�t�, Dibetou, Framir�, Limba, Krabak, Mukulungu, Niangon, East Indian jacaranda. Teak, Weng�
shakes	separations of the fibre structure which may occur as radial and tangential shakes		limited use, lower wood yield, possibly not usable as timber	almost all wood species described under 1.4.
resin galls, resin pockets	narrow tangential clefts in the trunk which are of varying length and filled with resins or latex *)		working is made more difficult, limited use, lower wood yield, lower strength	Bitangor, Bubinga, Makor�, Tiama, Yang, Zingana
false heartwood, coloured heart-wood	differently coloured inner zone or the trunk depending on the wood species (brown, yellowish, green and other colours)		lower wood yield, limited use, lower quality of the final product	Tiama
figured growth burls	great nodular accumulation of a large number of dormant buds concentrated in a very confined space		low strength, working is made more difficult
blue stain and other discoloration caused by fungi	blue stain, but also fungus attack occuring as blue-green or brown discoloration of the wood, which may be accompanied by decay or insect damage		limited use, surface treatment made more difficult, reduced impregnability	Abura, African mahogany, Ail�, Avodir�, Boss�, Douka, Ebiara, Framir�, Ilomba, Krabak, Limba, Makor�, Movingui, Naga, Okoum�, Ozigo, Sapelli, Tiama

*) latex: rubber milk

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	2. Materials Made of Wood
		2.1. Solid Wood
			(introduction...)
			2.1.1. Not Improved Solid Wood
			2.1.2. Improved Solid Wood
		2.2. Laminated Wood
		2.3. Sandwich Boards
		2.4. Fibreboards
		2.5. Particle Boards

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

2. Materials Made of Wood

2.1. Solid Wood

Solid wood is obtained from raw wood by longitudinal and cross cutting. It is used without or after improvement of the wood.

2.1.1. Not Improved Solid Wood

Name	Definition	Remarks
round timber	Round timber is obtained from rough wood by cross cutting. It includes saw logs, veneer flitches, masts, poles and others.	Saw logs and veneer flitches are intermediate products which are intended for further cutting.
Sawn timber	Sawn timber is produced by longitudinal cutting of round timber. Sawn timber has at least 2 parallel surfaces and is thicker than 5 mm.	Making of simple cut and double cut; simple cut:
		single passage through the machine yields untrimmed products; double cut:

		two passages through the machine; first passage is precut, edge boards and slabs are cut off; second passage is second cut; from the material turned by 90° the trimmed product is obtained.
Veneer	Is produced by longitudinal cutting (slicing, sawing) or arcuate cutting-off (peeling) of round wood; veneer is £ 3 mm thick and ³ 80 mm broad.

Kinds of sawn timber

Kinds Schematic representation		Width in mm (b)	Thickness in mm (s)
squared timber		>100	>100
frame timber		£ 2s	38...100
board (1) round-edged	(2) edge-trimmed	round-edged ³ 2 s edge-trimmed ³ 75	>16 16...100
lath		>75	16...35
ply		edge-trimmed ³ 75	6...15
strip		or round-edged < 75	6...15

Kinds of veneers

Kinds Schematic representation	Manufacture
sliced veneer	Sliced veneers are made by slicing off lamella by lamella in an operation similar to planing. Effective strokes of the machine: 16...36 min^-1 cutting speed: 0.5 to 1.5 m s^-1 length: up to 5 m thickness: 0.05 to 2.7 mm
1 knife, 2 knife holder, 3 veneer, 4 pressure strip, 5 pressure bar
peeled veneer	Peeled veneers are taken from a rotating trunk by an operation similar to turning. cutting speed: 0.2 to 2.5 m · s^-1 length: up to 4.5 m thickness: 0.08 - 2.7 mm
1 veneer knife, 2 knife holder, 3 veneer, 4 pressure strip, 5 pressure bar, 6 scratcher knife
saw veneer	Sawn veneers are produced with a horizontal frame saw or a veneer circular saw. Speed of the veneer frame saw: 200...300 min^-1 cutting speed: 6...8 m · s-1 length: up to 5 m thickness: 0.5 to 3.0 mm
1 saw blade, 2 compression roll, 3 veneer, 4 cleaving knife

2.1.2. Improved Solid Wood

Kind of solid wood	Manufacture		Application
compressed solid wood	solid wood compressed by pressing, beating or rolling under the influence of pressure and temperature		machine parts in the textile industry, bearing shells, press-drawing tools, etc.
impregnated solid wood	solid wood impregnated with various agents (e.g. resin, oil, metal) for changing its properties		synthetic resin-impregnated timbers in electric engineering, oil-impregnated wood as self-lubricating machine parts, metal-impregnated wood as slide bearing
formed solid wood		solid wood formed under the influence of temperature, moisture and pressure (by applying pressure on the cross-grain ends of the blank the latter is compressed and thus made bendable)	for bent parts in furniture construction, in vehicle construction and boat building, for the manufacture of sports equipment etc.

2.2. Laminated Wood

Laminated wood consists of veneer layers which are symmetrically laid one on top of the other. It is glued together by means of adhesive under pressure and temperature to form sheet material. Laminated wood has improved properties compared with solid wood and can be used for many more purposes.

Name	Material construction	Physical quantities	Application
plies (plywood)	symmetrical arrangement of the veneer layers, the layers are staggered alternately 90° according to the grain direction	r = 0.60...075 g · cm^-3 dzB =35...55 MPa ddB = 60...80 MPa dbB = 55...75 MPa	furniture industry, interior work, packaging industry, building industry etc.
laminated wood	veneers are arranged in parallel with each other (grain direction); up to 15 % vertically to it	r = 0.65...0.95 g · cm^-3 dzB =80...170 MPa ddB = 70...110 MPa dbB = 120..200 MPa	aircraft manufacture, shipbuilding, vehicle construction, timber engineering etc.
compressed laminated wood	arrangement of the veneers is the same as with plywood or laminated wood; by applying pressures of about 10 MPa compression is achieved (10 %)	r = 0.80...1.15g · cm^-3 dzB £ 220 MPa ddB £ 250 MPa dbB £ 250 MPa	machine parts, timber engineering, apparaturs construction, toolroom work, vehicle construction
plastic compressed laminated wood	same as compressed laminated wood, but made of synthetic resin-impregnated veneer	p = 1.15...1.35 g · cm^-3 dzB £ 140 MPa ddB £ 300 MPa dbB £ 240 MPa	vehicle construction, electric engineering, apparatus construction, timber engineering, machine parts

2.3. Sandwich Boards

Sandwich boards consist of a core and two cover plies, one on each side. Compared to the solid starting material considerable savings in material are possible and improved properties are reached.

Name	Material construction	Physical quantities	Application
sandwich board with solid wood core		r = 0.42...0.52 g · cm^-3 ddB = 12...38 MPa dbB = 30...40 MPa	furniture industry, interior work, pattern making, development working etc.
1 cover ply of crossband veneer; thickness ³ 1.8 mm 2 solid wood core of blackboard
sandwich board with hollow core		r = 0.01...0.04 g · cm^-3 dzB = 1.7 MPa ddB = 2.9 MPa dbB = 14 MPa	doors, partition walls, vehicle construction and shipbuilding, interior work, boat building
1 outer layers of veneer, plywood, hard fibre boards, metal or plastic boards; 2 core of paper honeycombs
sandwich board with particle board core	Particle boards as cores are coated on both sides with veneer or synthetic resin-impregnated papers. In this way their properties and appearance are improved.	r = 0.7...0.8 g · cm^-3 face strength » 0.9 MPa dbB » 40 MPa	furniture construction, interior work, ship building and waggon construction

2.4. Fibreboards

Fibreboards are a flat, sheet wood-based material made under the influence of pressure and temperature which consists of fibrous material cotaining lignocellulose.

Properties of fibreboards

Kind of board	Thickness in mm	Gross density r in g · cm^-3	Bending strength d_bB in MPa	Compressive strength d_dB in MPa	Transverse tensile strength d in MPa
hardened fibreboards	1...6	1.0...1.1	60	50...60	30...55
hard fibreboards	1...6	0.95...1.05	25...75	25...50	15...40
medium hard fibreboards	6...25	30...75	10...40	80	8...25
porous fibreboards	6...20	25...40	1.0...3.0	0.8...2.0	1.0...3.0
medium-dense fibreboards	10...19	0.60...0.85	15...32		0.3...0.7

Use of the fibreboards

Kind of board	Special features	Applications
medium-dense fibreboards	three-layer structure, high surface quality, homogeneous core structure, closed homogeneous narrow surfaces	same as (three-layer) particle boards for furniture, especially for visible outer surfaces of furniture
porous fibreboards	low density, low strength, heat-insulating	ceilings and panellings, roof sheathing, floor underlay
medium-hard fibreboards	heat-insulating	partition walls, panellings, roof sheathing
hard fibreboards	uniform surface, elastic, bendable, nailing and screwing possible	ceiling boarding and panelling, furniture parts, doors, partition walls, coverings
hardened fibreboards	oil-impregnated, especially abrasion-proof, water-repellent	panelling and sheathing outdoors, inner and outer doors, concrete moulds, floor, staircase and table coverings
sound-absorbing boards	porous fibreboards provided with holes, slits or similar for sound absorption	ceiling boarding and panellings in offices, telephone exchanges, cinemas, concert halls etc.
multilayer insulating boards	boards consisting of two or more layers of porous fibreboards glued in a water-proof manner	partition walls, displaceable walls, false ceilings
varnished boards	hard fibreboards with varnish coating	panellings in kitchens, shops, bathrooms, for furniture in rooms in which water is handled
sheet and plastic-coated fibreboards	hard fibreboards coated with coloured plastic sheets or synthetic resin-impregnated special papers	panellings in kitchens and bathrooms, for furniture in damp rooms, for table coverings in kitchens, shops, workshops, laboratories etc.
embossed fibreboards	hard fibreboards which during manufacture were given an embossed surface and (possibly subsequently) a colour treatment	for decorative purposes in interior work
floor boards	extra hard fibreboards which are laid like parquet, high wear resistance	for floor coverings
hard multi-layer boards	boards consisting of two or more layers of subsequently glued medium-hard or hard fibreboards	panels, shock-resistant coverings, partition walls, false ceilings

2.5. Particle Boards

The particle board is a wood-based material made of wood chips with the addition of synthetic resin under the influence of pressure and temperature. Its properties can be varied by the kind and quantity of the additives, by the quality and arrangement of the chips and the compression ratio.

Properties of the particle boards

Kind of board	Thickness in mm	Gross density r in g · cm^-3	Bending strength dbB in MPa	Transverse tensile strength r in MPa
single-layer flat pressed particle boards	6...25	0.5...0.85	15...20	0.2...0.3
triple-layer flat pressed particle boards	6...25	0.55...0.85	20...30	0.2...0.3
extruded particle boards	8...75	0.55...0.70	» 2.0 in pressing direction » 15.0 at right angles to the pressing direction	» 0.6 in pressing direction » 4.0 at right angles to the pressing direction

Use of the particle boards

Kind of board	Special features	Applications
flat pressed particle boards, raw, single-layer	dense surface, heat and sound-insulating, pressure-proof	interior work, building construction, agricultural building, floor underlays, insulating boards etc.
Flat pressed particle boards, raw multi-layer	like single-layer boards, but surface layer consisting of fine particles; dense surface, little swelling	manufacture of furniture, self-supporting structural elements, interior work, vehicle construction
extrusion particle boards, raw	low bending strength, coating absolutely necessary, in other aspects like single-layer boards	core for sandwich boards in furniture manufacture, in interior work, shipbuilding and vehicle construction, building industry
impregnated particle boards	additives are added to the binder, therefore resistant to temperature and wood pests	building industry, agricultural building, shipbuilding
veneer-coated particle boards	more resistant to varying climatic influences, better stability, higher bending strength	visible surface in furniture manufacture, interior work and shipbuilding, for panelling, cladding
particle boards coated with laminated boards, PVC-hard-boards or decorative laminates *)	coating on one side or both sides, higher strength, higher resistance to moisture and chemicals, scratch resistant	furniture in damp rooms, doors, partition walls, structural elements for walls, but also containers, concrete moulds, mainly in the kitchen furniture industry

*) decorative laminates: plastic sheets with wood pattern

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	3. Plastic materials
		(introduction...)
		3.1. Classification of Plastic Materials
		3.2. Properties of Important Plastic Materials
		3.3. Applications of Important Plastic Materials

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

3. Plastic materials

Plastics are synthetic materials or macromolecular organic-chemical materials produced by conversion of polymer natural products.

3.1. Classification of Plastic Materials

Type of plastics	Starting material	Chemical stability
Modified natural materials
cellulose nitrate	cellulose, nitric acid	resistant to weak acids and alkalis
Polycondensates (thermosetting plastics)
phenolic moulding compound	phenol or cresol, formaldehyde and filler materials	instable to concentrated acids and alkalis
phenolic laminates	phenol or cresol, formaldehyde and laminar substrates	same as phenolic moulding compounds
urea resins	urea or melamine resins and formaldehyde	same as phenolic moulding compounds
urea resin moulding compounds	urea or melamine resins, formaldehyde and filler materials	same as phenolic moulding compounds
urea resin laminates	urea or melamine resins, formaldehyde and laminar filler materials	same as phenolic moulding compounds
Polymerizates (thermoplastics)
polyvinyl chloride, rigid (unplasticized PVC)	acetylene and hydrocloric acid	instable to some organic compounds
polyvinyl chloride, flexible (plasticized PVC)	acetylene, hydroclorid acid and plasticizer	stability less than for rigid PVC
poloystyrene	ethylene and benzene	instable to most of the organic compounds
polyvinyl acetate	acetylene and acetic acid	(almost only improving or auxiliary agent)
Polyaddition products
polyurethanes	diisocyanates and dialcohols	instable to concentrated acids
Polyesterification products
polyester	carboxylic acid or phtalic acid and alkohols	instable to some organic compounds, when unsaturated
epoxy resins	epichlorhydrin, phenols	stable
alkyd resins	maleic acid and phtalic acid, multivalent alcohols	medium resistance to solvents and alcohols

3.2. Properties of Important Plastic Materials

Plastic material	Density in g · cm^-3	Temperature stability in ºC	Strain in %	Compressive strength ddB in MPa	Bending strength dbB in MPa	Tensile strength dzB MPa
cellulose nitrate	1.38	50	30...50	60	60	60...70
phenolic moulding compounds	1.4	125		120...200	50...70	25
phenolic laminates	1.4	125		140	120	40
urea resins	0.014 ...0.28		0.36	200	80	30
urea resin moulding compounds	1.45 ... 1.5	130		240	80	70
urea resin laminates	1.3 ... 1.45	130		150	150	120
rigid PVC	1.38	60	18	80	120	45...60
flexible PVC	1.23 ...1.36					8...25
polystyrene	1.04 ...1.09	60...90	1-20	45...120	70... 130	35...70
polyvinyl acetate				100	100	50
poly-urethane	1.2 ...1.215	<100	» 250	30...90	20...65	44...60
polyester	1.2...1.4	» 130		150	90	42
epoxy resins	1.2...1.25	60...120		90	135...150	72

3.3. Applications of Important Plastic Materials

Plastic material	Applications
cellulose nitrate	varnishes and adhesives
phenolic moulding compounds	preservative (see wood-based materials), adhesive and adhesive film, pimer paper for coating furniture elements varnishes, moulded parts
phenolic laminates	compression moulded sheets for coating kitchen furniture parts, but also laboratory furniture and similar
urea resins	adhesives, primer paper and decorative overlay for the furniture industry, foamed plastics and insulating materials, varnish resins
urea resin moulding compounds	moulded parts, e.g. for furniture fittings
urea resin laminates	decorative laminated sheets for kitchen furniture, laboratory furniture and damp rooms, decorative overlays for the furniture industry
rigid PVC	films, sheets, moulded parts
flexible PVC	flexible sheet as furniture fittings, decorative overlay and foam sheet, small surface tape for coating furniture veneered stock, overlapping edge bands, foamed plastics, varnishes
polystyrene	compression moulded sheets, furniture films, moulded parts, foamed plastics and varnishes
polyvinyl acetate	adhesives, surface coatings, oil-resistant sheets, varnishes
polyurethanes	adhesives, varnishes, rigid foamed plastics as insulation material and for furniture elements (seat shells), structural foam as moulded parts for furniture, semirigid foam for cushions, back-rests and similar, flexible foam for upholstery etc.
Polyester	adhesives, primer paper and decorative overlay, foamed plastics, varnishes
epoxy resins	adhesives and varnishes
alkyd resins	varnishes

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	4. Glass Materials
		(introduction...)
		4.1. Classification of Glass Materials
		4.2. Properties of Glass Materials
		4.3. Applications of Glass Materials

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

4. Glass Materials

Glass is a transparent, isotropic *) inorganic material.

*) showing the same physical properties in all directions of space

4.1. Classification of Glass Materials

Classification aspect	Glass grade	Remarks
flat glass	sheet glass	as thin, window and thick glass
	flat glasses with special effects, refined flat glass products	ribbed glass, antique glass, opal glass, frosted glass, plate glass, safety glass, thermoglass panes
fibre-glass materials	glas fibres	coarse glass fibres, textile fibres made of glass
	glass silk	superfine glass fibres

4.2. Properties of Glass Materials

Property	Sheet glass	Glass fibres
density r in g · cm-3	2.4...2.6	2.5
compressive strength ddB in MPa	800...1000
tensile strength dzB in MPa	70...90	850...4000 according to the thickness
bending strength dbB in MPa	50...150	170...3400 according to the thickness
temperature stability in °C	£ 500	-50...+300-C

Dimensions of sheet glass

Glass grade	thickness in mm	width in mm	length in mm
thin glass	0.9...1.6	300...700	1200...1400
window glass	2.0...4.0	300...1800	1000...2000
thick glass	4.5...5.5	400...2010	1050...2550

Dimensions of furniture glass

Glass element	thickness in mm	width in mm	length in mm
sliding doors	3.0...6.0	80...1200	100...1600
revolving doors	5.0...6.0	80...1200	100...1600
panels	3.0...6.0	80...1200	100...1600
glass tops	3.0...5.5	80...1200	100...1600
insertable plates	3.0...7.5	80...600	100...1600

4.3. Applications of Glass Materials

Material	Application	Remarks
thin glass	picture glass
window glass	glazing in housing construction and social buildings, furniture, glass-houses, stables etc.
thick glass	shop windows, shop fittings, furniture making
ribbed glass	shop building, interior work, kitchen furniture etc.	shaping is made during the drawing process
antique glass	interior work, period furniture	old glass is imitated by inclusions, staining and similar
opal glass	hospital windows, office partition walls and similar	toughened or etched panes
frosted glass	shop building, interior work, furniture	an opal glass from the frosted side of which flat splinters are torn out
plate glass	mirrors in flates and social buildings, vehicle construction, furniture making etc.	flat glass covered on one side with a silver layer of ³ 70 nm thickness; the silver layer is provided with protective layers
safety glass	skylights, glass-roofed courts, roof parts, doors, all-glass walls etc.	as wired glass (rolled in wire cloth), one-layer and multilayer safety glass and compound glass (flat glass panes bonded with transparent foil)
thermoglass panes	housing construction and social buildings	two window glass panes hermetically joined together enclose a space filled with dry air, which prevents misting up of the panes at outdoor temperatures down to -15 °C
glass fibres	building industry, machine building, textile industry	for heat and sound insulation, for reinforcement of plastic building materials
glass silk	structural elements, vehicle construction	processing with, for example, polyester resins into high-strength materials

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	5. Steel
		(introduction...)
		5.1. Classification of Steels
		5.2. Properties of Important Steels
		5.3. Applications of Important Steels
		5.4. Screws and Nails

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

5. Steel

Steels are ferrous materials which regardless of other alloying constituents have carbon contents of less than 2 %.

5.1. Classification of Steels

Classification aspect		Kinds of steels	Remarks
according to the manufacturing process		Bessemer steel Thomas steel open-hearth steel electric steel crucible cast steel	converter process like Bessemer steel open-hearth process made in the electric furnace remelting process in refractory crucibles
according to properties and application		general structural steels steels for mechanical engineering structural steels for special applications high-alloy special steels steels with special electric and magnetic properties tool steels	e.g. sectional steels e.g. screw steel e.g. wear-resistant steels e.g. corrosion-resistant steels e.g. dynamo sheet steels e.g. high-speed steels
according to the composition
	structural steel	unalloyed and alloyed steels	single-alloy steels (one alloying constituent); multiple-alloy steels (several alloying constituents)
	tool steels	unalloyed tool steels, low-alloy tool steels, medium-alloy tool steels, high-alloy tool steels
according to the form of production		sectional steel special profiles bar steel strip steel plate and sheet	e.g. U-steel, > 80 mm high e.g. rails e.g. U-steels, £ 80 mm high
		tube wire semifinished products forged pieces	e.g. plate > 4 mm thick, sheet < 4 mm thick seamless or welded various gauges and cross-sections sheet bars, billets etc. hammer and drop forgings

5.2. Properties of Important Steels

Name	Designation of the steel grade	Carbon content C in %	Tensile strength dzB in MPa	Alloying constituents in %
heat-treated steel	C 22	0.18...0.25	500...600	0.3...0.6 Mn, £ 0.045 P 0.15...0.35 Si £ 0.045 S
	C 35	0.32...0.40	600...720	0.4...0.7 Mn 0.15...0.35 Si £ 0.045 P and S each
	C 45	0.42...0.50	650...800	0.5...0.8 Mn 0.15...0.35 Si £ 0.045 P and S each
	C 60	0.57...0.65	750...900	like C 45
	30 Mn 5	0.27...0.34	800...950	1.2...1.5 Mn 0.15...0.35 Si
	37 Mn Si 5	0.33...0.41	900...1050	1.1...1.4 Mn 1.1...1.4 Si
	25 Cr Mo 4	0.22...0.29	800...950	0.5...0.8 Mn 0.9...1.2 Cr 0.15...0.35 Si 0.15...0.25 Mo £ 0.035 P and S each
	34 Cr Mo 4	0.30...0.37	900...1050	like 25 Cr Mo 4
	42 Cr Mo 4	0.38...0.45	1000...1200	like 25 Cr Mo 4
	50 Cr Mo 4	0.46...0.54	1100...1300	like 25 Cr Mo 4
	36 Cr Ni Mo 4	0.32...0.40	1000...1200	0.9...1.2 Cr and Ni each £ 0.035 P and S each
	34 Cr Ni Mo 6	0.30...0.38	1100...1300	1.4...1.7 Cr and Ni each £ 0.035 P and S each
	30 Cr Ni Mo 8	0.26...0.34	1250...1450	1.8...2.1 Cr and Ni each £ 0.035 P and S each
case-hardening steels	C 10	0.06...0.12	420...520	0.15...0.35 Si 0.25...0.5 Mn £ 0.045 P and S each
	C 15	0.12...0.18	500...650	like C 10
	15 Cr 3	0.12...0.18	600...850	0.4...0.6 Mn 0.5...0.8 Cr 0.15...0.35 Si £ 0.035 P and S each
	16 Mn Cr 5	0.14...0.19	800...1100	1.0...1.3 Mn 0.8...1.1. Cr 0.15...0.35 Si £ 0.035 P and S each
	20 Mn Cr 5	0.17...0.22	1000...1300	1.1....1.4 Mn 1.0...1.3 Cr 0.15,..0.35 Si £ 0.035 P and S each
	15 Cr Ni 6	0.12...0.17	900...1200	1.4...1.7 Cr 1.4...1.7 Ni, Mn, Si, P and S like 15 Cr 3
	18 Cr Ni 8	0.15...0.20	1200...1450	1.8...2.1 Cr 1.8...2.1 Ni, Mn, Si, P and S like 15 Cr 3

5.3. Applications of Important Steels

Steel grade	Applications
35 W Cr V 7,80 W V 2	machine blades
100 Cr 2	files
100 Cr 6	measuring instruments, saw blades for metal, cutting tools
64 Si Cr 5,85 Cr 1	saw blades for wood working
110 Mo V 5	metal saw blades
90 Cr 3	cutting tools
140 Cr 2,110 Cr 2,120 W V 4	twist drills
C 115 W 1	screws
C 100 W 1	cutters
C 130 W 2	files, flat drills, countersinks and counterbores
C 90 W 2	circular saw-blades, planing tools, cutters, cutter chain teeth, wood-carving knives
C 80 W 2	hammers, machine bits for wood
C 70 W 2	screw drivers, axes, pliers, vice jaws
C 60 W 3	wood working tools
C 85 W 6	hand saw blades, frame and circular saw blades
X 97 W Mo 3.3	twist drills
X 82 W V 9.2	high-speed wood working tools
X 86 W V 12.2	turning tools, cutters, twist drills
C 35, C 45, 25 Cr Mo 4	screws, nuts

5.4. Screws and Nails

(Material: unalloyed steel with low or medium carbon content, C = £ 0.55 %)

Name	Representation	Dimensions
raised countersunk head wood screws		d₁ = 1.6...8.0 mm d2 = 3.0...14.5 mm 1 = 8.0...90.0 mm
cross recessed raised countersunk oval head screw		similar dimensions
slotted round head wood screw		d₁ = 1.6...8.0 mm d₂= 3.2...16.0 mm 1 = 8.0...90.0 mm
cross recessed round head wood screw slotted countersunk head wood screw		similar dimensions d₁ = 1.6...8.0 mm d₂ = 3.0...14.5 mm 1 = 8.0...90.0 mm
cross recessed countersunk head wood screw hexagon head cap wood screw		similar dimensions d₁ = 6.0...12.0 mm d₂ £ d₁ 1 = 30.0...120.0 mm
countersunk-head nails		d = 1.4...6.0 mm 1= 20.0...200.0 mm
flat-headed nails		d= 0.8...4.6 mm 1= 8.0...130.0 mm
button-head nails		d = 0.8...2.5 mm 1 = 8.0...30.0 mm
upset-head nails		d = 1.0...3.8 mm 1= 14.0...100.0 mm
tin tacks		d₁ = 1.4...2.8 mm d₂ = 4.0...10.5 mm 1 = 10.0...40.0 mm
clout nails		like tin tacks
hardened nails		d= 1.2 and 2.0 mm 1 = 16.0...50.0 mm
light wood board nails		d= 3.1.; 3.4 mm 1 = 70.0; 80.0 mm

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	6. Basic Terms of Cutting
		(introduction...)
		6.1. Faces and Angles on the Tool
		6.2. Directions of Cutting
		6.3. Cutting Speeds
		6.4. Cutting-Edge Dulling and Cutting-Edge Wear

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

6. Basic Terms of Cutting

The science of cutting deals with the processes, laws and connections for chip-forming working with cutting tools.

6.1. Faces and Angles on the Tool

Term Representation	Symbol	Definition
primary cutting edge faces on the tool - saw tooth	HS	line of cut between flank and tool face
secondary cutting edge faces on the tool - milling tool	NS	cutting edge adjacent to the primary cutting edge
tool face faces on the tool - drilling tools	Sf	face on the cutting wedge on which he chip is removed
flank	Ff	face on the cutting wedge facing the area of cut produced on the work-piece
flank of the drill point	Hf	face on the tool next to the flank
comer	E	point on the tool at which primary and secondary cutting edges meet
tool orthogonal clearance angles on the tool - planing tool	a	angle between flank and tool cutting plane (plane through the cutting edge)
tool orthogonal wedge angle angles on the tool - saw tooth	b	angle between flank and tool face
tool orthogonal rake	g	angle between tool face and a vertical to the tool cutting plane g = 90º -a -b
cutting angle angles on the tool - drilling tools	d	angle between tool face and tool cutting plane d = a + b
tool cutting edge inclination angles on the tool - drilling tool	l	angle between cutting edge and tool reference plane
point angle	e	angle between primary and secondary cutting edges
drill point angle	eB	angle between two primary cutting edges, also called face angle

6.2. Directions of Cutting

The cutting direction of a cutting operation is the direction of motion of the primary cutting edge referred to the grain direction of the solid wood or the board plane of plane materials of wood.

Cutting directions in solid wood	Cutting directions in laminated wood	Cutting directions in particle and fibre boards

A cross-cutting cutting direction vertically to the grain direction; smooth area of cut, crumbly chip, short tool path	b cutting direction vertically to the board plane; approximately like cross-cutting of solid wood	b cutting direction vertically to the board plane; rough area of cut, crumbly chip
B longitudinal cutting cutting direction parallel to the grain direction; rough area of cut, coherent chip, long tool path	a/B cutting direction in board plane, in the direction of the grain direction of the top layer; like longitudinal cutting of solid wood	a cutting direction in board plane; cutting only in the top layer, smooth area of cut, crumbly chip
C transverse cutting cutting direction transversely to the grain direction; rough area of cut, brittle chip	a/C cutting direction in board plane and transversely to the grain direction of the top layer; like transverse cutting of solid wood

6.3. Cutting Speeds

Term	Symbol	Definition
cutting speed	v	speed at which the cutting edge of a tool performs chip-forming movements in the workpiece
		v = d · p · n	in m · s^-1
			d = diameter of the cutting circle of the tool
			n = tool speed
feed rate	u	speed at which the workpiece is fed to the stationary tool or the tool is fed to the workpiece clamped in place; unit of measurement: m · min^-1

Figure 3 Graph of cutting speeds for circular sawing machines

Example:

Which cutting speed does a circular saw blade having a diameter of 400 mm reach at a speed of rotation of 3000 min^-1?

Solution:

Find the diameter on the lower line, go vertically upwards to the point of intersection with the diagonal for n = 3000 min^-1, from there read off the result horizontally on the left side: v = 62.8m · s-1

Figure 4 Graph of cutting speeds for fluting machines

Example:

A cutting speed of approx. 15m · s^-1 is to be reached; the tool speed is 6000 min^-1.

Which tool diameter is to be chosen?

Solution:

Find the value for v on the left side, find horizontally the point of intersection with the diagonal for n = 6000 min^-1, from there drop a perpendicular and read off on the lower line: d » 50 mm.

6.4. Cutting-Edge Dulling and Cutting-Edge Wear

The loss of the original keenness (dressed keenness) of the tool cutting edge and the outer comers in the process of cutting is called dulling, its result is called wear.

Causes of wear

Cause of wear	Effect of wear
*Angles on the tool cutting edges*
wedge angle	The cutting forces rise with increasing wedge angle. Therefore, it must be kept as small as possible (taking into consideration the necessary stability).
rake angle	If the rake angle is too small, the consequences will be the same as with a too large wedge angle.
clearance angle	Large clearance angles result in a smaller load on the cutting edge (less friction and lower temperature).
*Cutting conditions*
cutting speed	High cutting speeds have the effect of increasing the load on the whole cutting wedge. For economical reasons they are to be kept as low as possible.
cutting depth	Keep it as small as possible. Great cutting depths lead to increasing mechanical stress on the cutting edges.
*Mechanical stresses*
friction	Excessive roughness of the cutting edge (choice of the proper abrasive tool) results in increased wear at the cutting wedge.
impact load	Mainly at the beginning of cutting when the cutting edge penetrates into the wood for the first time; it results in the loss of the original keenness.
compressive stress	The pressure of the workpiece on the tool is increasing with dulling (sharpening in time is necessary).
*Various kinds of stresses*
thermal stress	The friction between workpiece and tool produces temperatures of about 800 °C at the cutting edge. This results in softening of the cutting wedge surface and increased abrasion of material (proper choice of the cutting-edge material of the tool is necessary).
electrochemical stress	The diluted acids in the wood cells form electrolytes. In connection with frictional electricity produced during cutting the cutting-edge material is dissolved by electrolysis.
electroerosion	Spark discharges occur through electrostatic charges during cutting as a result of which particules are torn out of the flank. This formation of craters (increased roghness) favours the mechanical wear.

Forms of wear

Form of wear Representation	Influences and measurable variables
tool-flank wear	a result of mechanical wear, thermal load and electroerosion; the wear-land width is the measurable variable. This mark characterizes the size of the regrind, because the cutting edge has to be set back during sharpening so far that the wear mark disappears; wear mark for steel cutting edges s 0.3 mm.
cutting edge-wear	caused especially by thermal and frictional stresses; the external radius of the cutting edge is the measure of the cutting-edge wear;
corner wear	caused by the influence of friction and temperature; with increasing dulling the comer wear rapidly rises;
tool face wear	Apart from friction (flowing off chip) and temperature there is above all the electrochemical influence that is at work. The resetting of the cutting edge is the measure of the tool face wear (recommended dimension » 0.15).
crater wear	special form of the tool face wear as a result of friction and thermal influence by the flowing off chip
measurable variables of cutting-edge dulling 1 crater wear, 2 cutting-edge reset, 3 wear-land width, 4 cutting-edge rounding

Development of the cutting-edge dulling

Figure 5 Graph of cutting-edge dulling


cutting wedge (dressed keenness) with the original cutting-edge angles a₁, b₁ and g₁	cutting wedge (operating keenness) with the wedge angle b₂ that has become larger by incipient dulling and the tool orthogonal clearance a₂ that has become smaller and the tool orthog rate g₂	cutting wedge (advanced stage of dulling) with b₃ that has become still larger and a₃ and g₃ that have become still smaller

Dulling period of the cutting edge

Term	Symbol	Definition	Connections
tool life	T	pure operating time of a cutting edge between two regrinds	S = tool path W_t = path of cut per unit of time
tool path	S	distance travelled by the cutting edge cutting in the material between two regrinds	the tool path in connection with the tool life is an important parameter for the economical use of machine tools

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)
	7. Hand Tools
		(introduction...)
		7.1. Measuring and Marking Tools
		7.2. Sawing Tools
		7.3. Planing Tools
		7.4. Mortising and Ripping Tools
		7.5. Drilling and Boring Tools
		7.6. Rasps and Files
		7.7. Other Tools

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

7. Hand Tools

Hand tools are individually guided working tools by means of which action is taken on the object of work (workpiece) when the respective operations are carried out.

7.1. Measuring and Marking Tools

Marking tools serve the purpose of transferring sizes to the workpiece and of marking the transferred sizes.

Tool Representation	Construction and use
back square	The back square serves for marking out right angles. It has a shorter, thicker part (head piece, stop) and a longer, thinner blade (rail). It consists of wood or steel.
mitre rule	Mitre rules serve to mark out 45° angles, with the shorter leg serving as stop.
bevel gauge	Bevel gauges are back squares where both legs can be adjusted to each other as desired (angles of any size can be formed).
scratch gauge	The scratch gauge serves for marking out straight scribed linears parallel to one side of the workpiece. The stop is adjustable and is arrested by wedges or screws.
Compasses	The compasses serve for taking and transferring sizes and for marking out circular arcs.
1 guide beam, 2 centring point, 3 slide, 4 pencil holder

7.2. Sawing Tools

Hand saws have triangular teeth and consist of tool steel. We distinguish between span-web saws and saws without span web.

Untension frame saws after use, turn the row of teeth inwards during transport, saturate wooden parts with linseed oil varnish or with polish to prevent impurities from getting into them; keep hand saws in a hangig position, clean the saw blade from impurities by means of petroleum or similar and protect it against rust by means of acid-free grease. Cover the teeth of saws without span web during transport and storage so that no injuries are possible.

7.3. Planing Tools

Regularly clean the plane iron and the face of the plane; when putting the plane down, lay it on its side; the face of the plane must be even, if not, dress it and afterwards oil it slightly; replace faces of planes that are excessively worn by new ones; if the plane is blocking, check whether the flap is tightly fitting, the wedge is fitting or whether the pressure of the wedge is properly acting on the lower part of the plane iron.

7.4. Mortising and Ripping Tools

Mortising and ripping tools are hand tools for chiselling, mortising and turning operations.

The tool must be clean and sharp; always clamp the workpiece, always chisel on the carpenter’s bench plate, not on the collets; further hints: like plane irons.

7.5. Drilling and Boring Tools

Drilling and boring tools must be clean and well sharpened. When storing them, protect cutting parts. Keep them safe in a hanging or lying position in cabinets or cases, they must not contact each other. Remove impurities with hot water or petroleum after use, slightly grease them with acid-free grease against rust.

7.6. Rasps and Files

Rasps and files are hand tools for flattening and smoothing. Rasps have coarser cutting edges, files have finer ones.

Use only tools the tangs of which are straightly and firmly seated in the haft (stab injuries). Work in grain direction, if possible. Choose tooth spacing*) according to the wood quality (use files with coarse cut for soft or damp wood). Clean the tools from impurities by dipping them into hot water, brush them with a hand brush. Clean metal files with file brushes made of fine copper wires.

vernier caliper with depth gauge	Length measurements are possible by placing the workpiece between graduation carrier and sliding member. The diameter of bore holes can be measured with the sensing elements. For determining the depth of bore holes and similar the depth gauge is used.
1 measuring surface of the graduation carrier, 2 measuring surface of the sliding member, 3 sensing element for determining the diameter of bore holes, 4 depth gauge
outside caliper	caliper-like measuring instrument (caliper) with inwardly bent legs for tracing and comparing diameter, lengths and tick-nesses
inside caliper	caliper-like measuring instrument (internal caliper gauge) with outwardly bent leg points for tracing and comparing bore holes, counterbores and similar
radius gauge/profile gauge	Radius gauges are templates like profile gauges and similar, by means of which the profiles of boards, but also of narrow surfaces can be checked.

Kind of saw	length in mm	Saw blade width in mm	thickness in mm	Saw pitch in mm	Setting width in mm	Applications
foxtail	250-500		0.7-0.8	3-5	0.2-0.25	fine work, cutting of plywood and other materials
keyhole saw	300		1.0	4	0.35	for cutting out openings
fine saw	250	65	0.5	1.5	0.15	especially for mitre cuts
back saw	300	100	0.7	3-4	0.2	like fine saw

Kind of saw	Saw blade
	length in mm	width in mm	thickness in mm	Saw pitch in mm	*Setting width) in mm**	Applications
cabinet saw	700;800	25	0.7	5	0.4	for work in grain direction; trimming, cutting off
pad saw	700:800	40	0.7	4	0.25	finer cuts across the grain direction, for wood-based materials
fret saw	700	10	0.7	3	0.25	for sawing out bends

Kind of saw	Angle at the a tool cutting edge in °
	a	b	g
cabinet, pad, fret saws	45	70	-25
foxtail saw, keyhole saw	60	60	-30
fine saw	65	50	-25
back saw	10	60	20

Kind of plane	Cutting angle d in º	Applications
finish plane	45	without flap; coarse chip removal, for flattening and rough smoothing, chip thickness up to 1 mm
1 plane knife, 2 plane body, 3 chip hhole, 4 workpiece, 5 chip, 6 wedge angle, 7 cutting angle, 8 flap of the plane
double iron plane	45	with flap, smoother surface than with the finish plane, for flattening of finished surfaces
1 plane knife, 2 plane body, 3 chip hole, 4 workpiece, 5 chip, 6 wedge angle, 7 cutting angle, 8 flap of the plane
trying plane	45	with flap; basically a long double plane; for dressing of surfaces, for edging and jointing of narrow surfaces
smoothing plane	49	with flap; for smoothing of surfaces, for planing of end surfaces
1 plane knife, 2 plane body, 3 chip hole, 4 workpiece, 5 chip, 6 wedge angle, 7 cutting angle, 8 flap of the plane
rabbet plane	45...48	simple rabbet plane without flap, double rabbet plane with flap; for replaning and resmoothing of rebates

Tool		Dimension of the blade
		width in mm	thickness in mm	Applications
ripping chisel	light medium heavy	4...50 6...40 20...35	2.5...4 3.5...4.2 4.2...5	for mortising recesses, for recessing fittings, for mortising recesses at an acute angle
mortise chisel		2...26	12...15	for mortising orftenon holes and similar
turning chisel, flat		4...50	3.5; 4.5	making of turned bodies, soft wood working, finishing work; a = 10...20^º b = 20...30^º
turning chisel, hollow		4...50	3.5...6	hard wood working, roughing work; a = 10...20^º b = 40...50^º

Drilling and boring tool	Dimensions in mm		Applications
twist drill with roof-shaped point	diameter thread length	3.0...8.3 42...70	for drilling into hard wood and end-grained wood, into wood-based materials and metals
twist drill with a spiral flute	diameter overall length	2...12 120...170	for drilling into end-grained wood
auger bit	diameter length	6...30 185...250	for deep drilling into soft and hard wood
twisted auger	diameter length	3...10 125...160	mainly for predrilling for woods screw into soft wood; produces high splitting effect
centre bit	diameter length	6...50 80...140	drilling into cross pieces
grimlet	diameter length	2..10 90...200	for predrilling screw and nail holes, mainly into soft wood
wood countersinks	diameter length	16 and 20 100	for reaming bore holes, these get a funnel-shaped bevel

Feature	Application
with square shank	for breast drill
with parallel shank	for drill chuck and machine
with entering tap	for cross-piece drilling
with chip groove	for deep drilling
with roof-shaped point	for non-fibrous materials and end-grained wood
with centre point	for exact advance
with feed thread	for manual work
without feed thread	for machine work
with short die head	for flat drilling

Tool	Length in mm	Cross-section in mm	Application
flat rasp 1 width, 2 thickness	200...350	20 × 5...36 × 8	Rasps serve for coarse smoothing of round portions and recesses.
half-round 1 width, 2 thickness	200...300	18 × 6...30 × 10
round rasp 1 width	200...250	diameter 8 and 10 mm

Tool	Application
glass cutter	for cutting glass panels. The glass is scratched under slight pressure by means of a diamond particle or a hard metal tip.
setting iron	for setting hand saws. The tool head provided with the recesses may have a varying number of notches; the notches are of different widths and correspond to the different thicknesses of the saw blades.
setting pliers 1 adjusting screw for tooth depth 2 adjusting screw for setting width	for setting hand and machine saw blades. The setting pliers are designed for various tooth depths and blade thicknesses; setting depth and setting width can be adjusted. The setting pliers allow more exact working than the setting iron.
setting pliers for tooth depths of up to 8 mm and blade thicknesses of 0.3...1.5 mm 1 adjusting screw for tooth depth 2 adjusting screw for setting width
setting pliers for tooth depths of up to 15 mm and blade thicknesses of 0.5...3.0 mm
hone	for honing (smoothing) the cutting edge. Natural as well as synthetic stones are used, with the latter mostly having on both sides different grain sizes (rough honing, fine reworking). Water and oil are used as lubricants.
scraper	for smoothing hard wood surfaces. Chip removal by sharp burrs on the longitudinal edges; 0.8 - 3 mm thick, made of tool steel

tool diameter	250...600 mm
tool speed	1500...4500 min^-1
dimensions of the main table	1000 mm × 1200 mm
dimensions of the sliding table	750 mm × 350 mm
input power	2.5...5.6 kW

tool diameter	300...600 mm
tool speed	» 3000 min^-1
swiveling angle of the saw blade	£ 45°
width of the cut	£ 600 mm
height of the cut	£ 150 mm
input power	2.0...5.5. kW

saw-blade length	3000...5500 mm
saw-blade width	5...60 mm
speed of the band saw guide rollers	650...950 mm^-1
roller diameter	300...850 mm
depth of throat (cutting width)	350...900 mm
workpiece thickness	£ 500 mm
input power	1.0...5.5 kW

diameter of the blade shaft	100... 125 mm
speed of the blade shaft	4500...6000 min^-1
number of blades	2; 4
length of the feeding table	1100...1600 mm
length of the unloading table	1100...1500 mm
working width	400...600 mm
input power	3.0...6.0 kW

diameter of the blade shaft	100...125 mm
speed of the blade shaft	4500...5500 min^-1
number of blades	2; 4
feeding speed	4...30 m/min
workpiece length ³ 200 mm
workpiece width	5...800 mm
workpiece thickness	3...300 mm
input power	4...7.5 kW

length of the machine table	800... 1200 mm
width of the machine table	500...1000 mm
height of the machine table	850...900 mm
cutter arbor diameter	30; 40 mm
spindle speed	1200...12,000 min^-1
input power	1.0...12.0 kW

tool diameter	4...25 mm
spindle speed	1400...10,000 min^-1
drilling depth	£ 100 mm
length of the longitudinal slot	£ 200 mm
input power	1.5...5 kW

centre distance	1000...2000 mm
centre height	200...400 mm
work diameter above gap	£ 750 mm
length of the workpiece to	£ 225 mm
be turned in the gap spindle speed	250...2500 min^-1
speed increments of the spindle	» 9
input power	1.5...2.5 kW

tool diameter	£ 40 mm
speed of the tool spindle	150...4500 min^-1
travel of the tool spindle £ 150 mm
length of the support table	250...450 mm
width of the support table	200...350 mm
input power	0.7...2.5 kW

sanding belt width	150...500 mm
sanding belt speed	15...30 m/s
belt roller diameter	» 300 mm
distance between belt roller centres	» 3000 mm
belt roller speed	» 1500 min^-1
length of the supporting table	1000...2500 mm
width of the supporting table	300... 1000 mm
input power	3...10 kW

sanding disk diameter	600...1300 mm
speed of the sanding disk	750... 1500 min^-1
input power	3.0...7.5 kW

diameter of the sharpening wheel	£ 200 mm
speed of the sharpening wheel	» 3400 min^-1
grinding speed	» 35 m/s
motor power	0.5 kW

Preface

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

1. Wood

1.1. Structure of Wood

1.2. Chemical Composition of Wood

1.2.1. Cell Wall Components of Wood

1.2.2. Wood Constituents

1.3. Physical Properties of Wood

1.3.1 Wood Density

1.3.2. Moisture Content of Wood

1.3.3. Swelling and Shrinking of Wood

1.3.4. Thermal Properties of Wood

1.3.5. Acoustic and Electric Properties of Wood

1.3.6. Friction Properties of Wood

1.3.7. Strength of Wood

1.4. Important Wood Species

1.5. Wood Defects Caused by Growth Influences

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

2. Materials Made of Wood

2.1. Solid Wood

2.1.1. Not Improved Solid Wood

2.1.2. Improved Solid Wood

2.2. Laminated Wood

2.3. Sandwich Boards

2.4. Fibreboards

2.5. Particle Boards

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

3. Plastic materials

3.1. Classification of Plastic Materials

3.2. Properties of Important Plastic Materials

3.3. Applications of Important Plastic Materials

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

4. Glass Materials

4.1. Classification of Glass Materials

4.2. Properties of Glass Materials

4.3. Applications of Glass Materials

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

5. Steel

5.1. Classification of Steels

5.2. Properties of Important Steels

5.3. Applications of Important Steels

5.4. Screws and Nails

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

6. Basic Terms of Cutting

6.1. Faces and Angles on the Tool

6.2. Directions of Cutting

6.3. Cutting Speeds

6.4. Cutting-Edge Dulling and Cutting-Edge Wear

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

7. Hand Tools

7.1. Measuring and Marking Tools

7.2. Sawing Tools

7.3. Planing Tools

7.4. Mortising and Ripping Tools

7.5. Drilling and Boring Tools

7.6. Rasps and Files

7.7. Other Tools

Formulae and Tables - Wood / textbooks for vocational training (GTZ, 122 p.)

8. Wood Working Machines

8.1. Sawing Machines

8.1.1. Circular Saw Benches

8.1.2. Parallel Rocking Circular Sawing Machine

8.1.3. Table Band Sawing Machine

8.2. Milling Machines

8.2.1. Smooth Miller

8.2.2. Thicknessing Miller

8.2.3. Shaping Machine

8.2.4. Slot Milling Machine

8.3. Lathe

8.4. Drilling Machines

8.4.1. Box-Column Drilling Machine

8.4.2. Hand Drilling Machine

8.5. Sanding Machines

8.5.1. Horizontal Belt Sanding Machine

8.5.2. Column-Type Disk Sanding Machine

8.6. Presses

8.7. Sharpening Machines

8.7.1. Ripping Chisel and Plate Iron Sharpening Machine

8.7.2 Sharpening Machine for Circular and Band Saw Blades

8.7.3 Milling Cutter Sharpening Machine

diameter of the circular saw blade	160...1200 mm
width of the band saw blade	³ 10 mm
saw pitch	5...60 mm
tooth height	3...30 mm
tool orthogonal rake g	15...30°
tool cutting edge inclination a	8...15º
diameter of the grinding wheel	£ 200 mm
speed of the grinding wheel	2800 mm^-1

cutter diameter	£ 200 mm
grinding length	£ 150 mm
speed of the sharpening wheel	1400; 2800; 3500 min^-1
input power for sharpening wheel motor	0.6 kW
input power for feeding motor	0.25 kW
input power for coolant pump	0.13 kW

grinding length	800...4500 mm
blade width	£ 250 mm
feeding speed of the grinding unit	8...16 m/min
grinding speed	» 30m/s
diameter of the sharpening wheel	175...200 mm
grinding infeed	0.002...0.3 mm
input power for the sharpening wheel motor	3.0...5.0 kW
input power for the travelling drive	» 0.75 kW
input power for the coolant pump	» 0.1 kW

Number of cutting edges per tooth	1	1	1	1	1	1
Representation
Symbol Name	N acute-angled tooth	K gullet tooth	p raven beak tooth	A triangular tooth	Y roof-shaped tooth	S -
Number of cutting edges per tooth	2	2	2	2	3
Representation
Symbol	X	M	Z	B	W
Tooth gullets
Representation
Symbol	C	V		U

Diameter in mm	KV teeth		NV teeth g > 0º		NV teeth g = 0°		AV teeth
	z	t	z	t	z	t	z	t
	in mm		in mm		in mm		in mm
80			64	4.2
100			64	5.2
125			80	4.9
160			80	6.3
200			80	7.8	80	7.8
250			80	10	80	10
300	56	17	80	12	80	12	72	13
350	56	20	64	17	64	17	72	15
400	56	22	64	20	64	20	72	18
450	56	25	64	22	64	22	72	20
500	56	28	64	25	64	25	72	22
550	56	31	64	27	64	27	72	24
600	56	34	64	30	64	30	72	26
650	56	36	64	32	64	32	72	28
700	56	39	64	35	64	35	72	31
750	56	42	64	37	64	37	72	33
800	56	45	64	40	64	40	72	35
Application	for longitudinal cuts at normal load with manual feed		for longitudinal cuts at normal load in hard and soft wood with manual feed		for cross cuts at normal load in hard and soft wood with manual feed		for cross cuts at normal load and with manual feed

Cutting direction	Application	Tooth form	Tool orthogonal rake g in °	Wedge angle b in °	Plan angle c in °	Setting width a in mm
longitudinal cutting	hard wood	KV, PV	22	46	87	0.35
		NV	18	40	87	0.35
	softwood	NV, KV	28	40	87	0.45
	dry	PV
	softwood	NV, KV	28	40	87	0.45...0.40
	damp	PV
cross cutting	hard	NV	19...2	35...48	65...70	0.45
	and softwood	AV	-10...-38	40...58	65...70	0.25

Saw pitch t in mm	Tooth height h in mm	Setting width a in mm	Tool orthogonal clearance a in °	Wedge angle b in °	Tooth form	Application
12	4...5	0.4...0.5	20	45	NV	for sawing soft wood
10	3...4	0.3...0.4	30	55	NV	for sawing hard wood
8	3	0.3	30	55	NV	for sawing laminated wood, sandwich, particle and fibre boards

Crown cutter	Relief-turned cutter	Relief-milled cutter or relief-ground cutter

the flank is hollow-ground, so that symmetrical pairs of cutting edges are produced	the flank is curved (relief-turned) so that there will be no friction between tool (flank) and workpiece	the flank is straight (by relief milling or relief grinding)
for operations requiring a change of the direction of rotation of the tool; it is disadvantageous that the unused cutting edge is rubbing against the workpiece and gets dull as a result of this	mainly for rebating and form milling tools; to maintain the profile regrinding is made only at the tool face	mainly for grooving cutters

Kind of cutter	Dimensions in mm
jointing cutter	diameter	63...80
	working width	28...63
rebating cutter	diameter	63...180
	working width	16...40
bevelling cutter	diameter	70...180
	working width	12...45
half astragal cutter	diameter	63...160
	working width	11 ...90
quarter astragal cutter	diameter	63...180
	working width	8...51
moulding cutter	diameter	63...140
	working width	2.5...25
half moulding cutter	diameter	63...180
	working width	8 ...51
cornice cutter	diameter	100...180
	working width	22...65
grooving cutter	diameter	80...125
	working width	4...14
cornice cutter with plate	diameter	80...200
	working width	12...42

Application	Tool orthogonal clearance a in º	Tool orthogonal wedge angle b in °	Tool orthogonal rake g in °
Softwood
cutting direction A	6...10	40...50	30...45
cutting direction B	8...15	45...55	20...35
cutting direction C	4...8	45...55	25...40
Hardwood
cutting direction A	8...12	45...55	25...35
cutting direction B	8...12	55...65	15...25
cutting direction C	6...10	55...60	20...30
chip board, uncompressed laminated wood	5...10	55...60	20...25
hard fibre board, compressed laminated wood	5...10	60...65	15...20