CHESTER Craftsman, Instruction Manual

Page: 23 / 53

Screw Cutting
During this module you are required to explore the use of the lathe to cut, amongst other things, a metric
screw thread on a bar. It is a slightly more difficult task than plain turning because it involves accurate
setting up of the tool and exact setting of feed in relation to the work rotation. Once this is done however,
and this you will be shown, the process of screw cutting becomes relatively simple. Fig 10 shows the
arrangement in simplified form.
Figure 10. Screw Cutting Set­up
There are many different forms of screw thread; Fig 11 shows the 'sections' of three most common types.
More types and specifications of screw threads can be found in any Workshop Technology Hand Books
and you must get used to finding such information and knowing how to apply it.
Figure 11. Types of Screw Thread
Chester UK Craftsman Lathe
22