Raw material quality control
1. Strictly implement qualified supplier evaluation: Currently, most of our raw materials are purchased from Shanghai Baosteel, Yongxing Special Steel, Shanghai Yatai, and other well-known large and medium-sized domestic steel mills for pipe billets and round bars
2. Raw materials undergo chemical composition testing, dimensional tolerance testing, and inspection of internal and external surface defects
process control
1. Self inspection of each process, mutual inspection between upper and lower processes, and quality assurance inspection
2. Heat treatment control: Advanced heat treatment furnace controlled by computer, using liquefied gas as fuel, with stable temperature, good heat treatment effect and environmental protection; After each batch of heat treatment, samples are taken for physical performance testing to ensure product quality;
Finished product control
1. 100％　 
2. Dimensional Inspection
3. Internal and external surface inspection
4. Physical performance testing: flattening, stretching, expanding, hardness test
5. Non destructive testing: eddy current testing, ultrasonic testing
6. Corrosion resistance test: intergranular corrosion test, pitting corrosion test
7. Hydrostatic test
8. Grain size test