1. General

Filleting techniques

There are a number of different techniques for producing threads in metals. Basically, threading techniques are based on one of two principles. The first is shaping by material removal (cutting, electroerosion). The second is shaping by plastic deformation. Tapping is the only technique that uses either material removal or plastic deformation of the material, a technique known as deformation tapping. There is also an EDM thread-machining technique, which is similar to tapping. Each technique has its own thread-producing capabilities, particularly in terms of thread shape, size and quality. Table 1 summarizes the comparison of threading techniques.

Internal threads are mainly produced using one of the tapping techniques. This is because...