Typical Processing Routes (II)

3.1 General Inspection

1. Review of accompanying technical documents and certificate of quality

2. Visual Inspection

1. Whether the supplier identification and property class marking are applied as required.

2. Appearance of the fastener

The surface shall be clean, smooth, free from burrs, rust, missing threads, damaged threads, and the coating shall be free from defects such as bubbles or peeling. The coating thickness shall meet the standard requirements.

3.2 Dimensional Inspection

Inspection shall be carried out in accordance with the relevant national standards or technical requirements (agreements, specifications, drawing requirements, etc.)

1. For bolts, screws, studs, and nuts, inspect the thread length, nominal thread diameter, head thickness, shank diameter, nut height, straightness, etc. Use the corresponding thread go and no-go gauges for inspection.

2. Bolts and screws before plating shall be inspected using a ring gauge of tolerance class 6g; after plating, they shall be inspected using a ring gauge of class 6h.

3. Nuts before plating shall be inspected using a thread ring gauge of tolerance class 6G; after plating, they shall be inspected using a thread plug gauge of class 6H.

4. For go gauge inspection, it is acceptable if each thread can pass through smoothly. For no-go gauge inspection, it is acceptable if the no-go gauge passes through no more than two threads.