A thread is a helical geometry with certain parameters such as outer diameter, inner diameter, pitch, and helix angle. In machining, the thread is machined onto the surface of the part, which can play the role of fixing and transmission.
Common threads include triangular threads, rectangular threads, and round threads, among which triangular threads are the most common.
There are two main methods of thread processing: one is internal tapping, that is, machining threads in the hole; the other is external tapping, that is, machining threads on the shaft. In CNC lathe processing, the main processing method is external tapping.
