Threading is the process of creating a screw thread. More screw threads are produced each year than any other machine element. CWS’ offer offsite and onsite rethreading services for our clients.
A common method of threading is cutting with taps and dies. Unlike drill bits, hand taps do not automatically remove the chips they create. A hand tap cannot cut its threads in a single rotation because it creates long chips which quickly jam the tap (an effect known as “crowding”, possibly breaking it. Therefore, in manual thread cutting, normal wrench usage is to cut the threads 1/2 to 2/3 of a turn (180-to-240-degree rotation), then reverse the tap for about 1/6 of a turn (60 degrees) until the chips are broken by the back edges of the cutters.
Today engine lathes and CNC lathes are the commonly used machines for single-point threading for offsite services. On CNC machines, the process is quick and easy (relative to manual control) due to the machine’s ability to constantly track the relationship of the tool position and spindle position.