1. Small size bolts below 8.8 (M16 and below)
Raw material selection: low carbon steel (Q235, 08, 10, 18, etc.)
Blank forming method: cold heading
Thread forming: rolling or thread rolling (selection method of rolling or thread rolling)
Routing:
Raw materials (selected materials) — material transformation — cold heading — turning (chamfering, flat end) — thread rolling or thread rolling — surface treatment (as required) — final inspection — packaging
2. Large bolts of 12.9 (M16 and above)
Raw material selection: medium carbon alloy carbon steel (35CrMo, 42CrMo, SCM435, etc.)
Blank forming method: Hung Hom
Thread forming: rolling
Routing:
Raw materials (selected materials) — material restructuring — blanking — turning processing (turning slabs) — Hung Hom — turning processing (turning head, chamfer, flat end, flat length, etc.) — (marking) — (shot blasting) — grinding Cutting (screw grinding)-rolling-dephosphorization-heat treatment-flaw detection-surface treatment-final inspection-packaging
3. Screw nut processing technology
Screw nuts made of red cymbals (large size)
Material selection (according to screw nut performance requirements)
Routing:
Material transformation—cutting—turning (mainly threaded bottom hole, flat end guaranteed height) — (marking) — tapping — (heat treatment) — surface treatment — final inspection — packaging
Material transformation—cutting—turning (mainly threaded bottom hole, flat end guaranteed height) — (marking) — (heat treatment) — tapping — surface treatment — final inspection — packaging
Whether the screw nut is heat treated depends on the mechanical properties of the nut.
