Thread Machining Methods

Tapping (Internal Threads)

Cut tap: standard for through holes. Form tap: roll-formed by displacement — stronger, no chips, 1.5-2× faster. Blind holes: drill depth = thread depth + 3× pitch.

Thread Milling

Multi-tooth cutter using helical interpolation. One tool for multiple sizes. Excellent for >M24. Best for hard materials (HRC 45+).

Thread Rolling

Cold-forming between dies. 20-30% stronger than cut. Surface finish 0.2-0.8 µm Ra. Up to 60 parts/min for M12.

Thread Turning

CNC single-point (G76/G92). 4-8 passes. Full-form carbide inserts. Class 2A/2B standard; 3A/3B with close control.