| Category | Raw Material | Cold Forming | Thread Rolling | Heat Treatment | Surface Treatment | Quality Inspection |
| Key point of quality assurance | Mechanical properties Size(DIM’S) |
Size(DIM’S) Metal flow |
Thread precision degree LAP |
Hardness(deep, surface) Tensile strength Structure-(de)carburization |
Chemical analyzing control Plating thickness Anti-corrosion |
In-process inspection Final inspection Incoming inspection Reliability inspection |
| Inspection and measuring equip | Universal testing M/C Hardness tester Metallurgical microscope M/M,V/C |
M/M V/C Profile projector Hommel profile tester Concentricity tester |
M/M V/C Profile projector Hommel profile tester Microscope RING G/A |
Universal testing M/C Hardness tester Metallurgical microscope |
Tester of coating thickness Salt spray test box Combined cyclic corrosion tester Chemical analyzing instruments |
Reliability test equip Dimensions checking gau |
