Thread classification and thread processing（二）
Second, thread processing
1. Die
The method of machining threads directly with a die
2.Rolling
This is a method to obtain threads by plastic deformation of the workpiece with a forming and rolling die. Thread rolling is generally done on a thread rolling machine. It is suitable for mass production of external threads of standard fasteners and other threaded joints.
3. Cutting
This refers to the method of machining threads on the workpiece with a forming tool or abrasive.
4.Thread milling
Milling is performed on a thread milling machine with a disc or comb milling cutter. The disc milling cutter is mainly used for milling the thread milling trapezoidal external threads on the workpiece such as screw and worm.
5. Thread grinding
It is mainly used for machining the precision threads of hardened workpieces on thread grinding machines, and is divided into single-wire and multi-wire grinding according to the shape of the grinding wheel cross-section.
6. Thread grinding
A nut or screw type thread grinding tool made of soft material such as cast iron is used to grind the machined threads on the workpiece in the forward and reverse direction to improve the pitch accuracy. Hardened internal threads are also usually ground to eliminate deformation and improve accuracy.
7. Tapping and threading
Tapping is to screw the tap into the pre-drilled bottom hole of the workpiece with a certain torque to produce internal threads. The external thread is cut on the bar (or tube) workpiece by using the plate.
