The threading holder is a throwaway holder used for threading in turning. There are two types of threading holders, one for the inner diameter and the other for the outer diameter. The turning holder is mainly a square shank, and the boring holder is mainly a round shank. The square shank or round shank size is selected according to the processing machine used. Depending on the holder, there are right hand only, left hand only, and no hands (for both), so select according to the machining direction. Threaded holders can be processed with various specifications such as metric threads, unified screws, etc. and various screw pitches by exchanging the tips, but confirm and select the corresponding tip and holder specifications because there are minimum inner diameters.