Method of Thread CNC Machining

1. Rolling thread processing.

Rolling thread processing is using the forming rolling die, to produce plastic deformation of a workpiece, to machine the thread. It is usually used for machining male threads. And this method is suitable for the mass production of standard fasteners. The outside diameter of the rolling thread is generally not more than 25mm, the length not more than 100mm, thread accuracy can be reached grade 2. And the hardness of material raw is not exceeding HRC40.

2. Milling thread processing.

Milling with a disk tool or comb tool on a thread milling machine is milling thread processing. Thread accuracy can be reached grade 8~9, the surface roughness is R5~0.63 micron. This method is suitable for batch production of thread part of general precision or rough machining before grinding.

3. Grinding thread processing.

Mainly used for machining precision thread parts of hardened item on thread grinding machines. The thread accuracy of single-line grinding wheel is grade 5~6, and the surface roughness is R1.25~0.08 micron. This method is suitable for grinding precision lead screw, thread gauge, worm, small batch thread parts and shovel-grinding precision hob.

4. Tapping thread and mantle fiber.

Tapping is to use a certain amount of twist, to screw the tap into the predrilled bottom hole of the workpiece, to process the internal threads. Mantle fiber is to use die to process external thread on the rod (or pipe) workpiece. Small diameter internal thread can only be machined with taps.

5. Turning thread processing.

Turning thread on lathe can be completed by shaping turning tool or a threading comb tool. Turning threads by the forming turning tool, is a common method to process thread item in single piece and small batch, since the simple in structure of the tool. It is efficient to turn threads with a threading comb tool, but since the complicated structure of the tool, it is only suitable for the short thread items, of turning fine teeth in medium, and mass production. Thread accuracy is grade 8~9 for turning thread by the plain lathe. And it can be reached higher production efficiency and accuracy, by the specialized thread lathe.