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		Threaded Joints - Course: Techniques of fitting and assembling component parts to produce simple units. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 25 p.)
			(introduction...)
			Preliminary Remarks
			Hints on Labour Safety
			1. Purpose of Threaded Joints
			2. Selected Types of Bolts and Screws
			3. Selected Types of Nuts
			4. Selected Types of Locking Devices for Bolts and Screws
			5. Selected Types of Washers
			6. Types of Threaded Joints
			7. Stresses in Threaded Joint
			8. Tools
			9. The Technological Steps of Making Threaded Joints
			10. Undoing Threaded Joints

1. Purpose of Threaded Joints

Threaded joints are detachable joints of two or more component parts either directly connected with each other or by standardized fasteners, i.e. bolts, nuts and screws.

Figure 1. Typical example of a threaded joint

Threaded joints are made

- to keep the component parts of the detachable joint in a desired position,
- to provide the force required to produce a joint and maintain this force for the intended period.,
- to transmit motions and forces of component parts.

Suitable locking devices are used where detachable joints have to be secured against the accidental loosening due to the action of dynamic stresses, such as vibration or shock.

No locking devices are required on temporary joints with fine-pitch thread and joints in which the component parts are self-tightening by the sense of their rotation (e.g. drill chucks on hand drills).

What is a threaded joint?
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What requirements must be met by a threaded joint under a dynamic stress?
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