Unit 2

Usually manufactured from low or medium carbon steel. Adv. of using nuts and bolts is that they can be easily undone, allowing components to be replaced or repaired.

Screwhead terminology

• Pitch - Distance from each 'ring' around the screw
• Crown - The highest point of a 'ring'
• Core diameter - Distance of middle of screw before each 'ring' starts.
• Outside diameter - Distance from highest to lowest point of whole screw.

Various screw threads:

• V-thread, Acme thread, Square thread, Buttress thread.

Cutting threads in holes:

The correct term for putting a thread into a hole is 'tapping'. The first consideration when tapping a hole into which the thread is…