Standard parts on the market now mainly include carbon steel, stainless steel, and copper.

Carbon steel. According to the carbon content of carbon steel, it can be divided into low carbon steel, medium carbon steel, high carbon steel and alloy steel.

1. Low carbon steel C%≤0.25% is usually called A3 steel in China. Overseas, its basic name is 1008101510181022. Suitable for products with non-hardness requirements such as grade 4.8 bolts, grade 4 nuts, small screws, etc. (Note: 1022 material is mainly drill tail nail material.

2. 0.25% medium carbon steel

1039.40ACr and so on. Mainly used for grade 8 nuts, grade 8.8 bolts and grade 8.8 hex products.

3. C%> 0.45% of high carbon steel. Not available in the current market.

4. Alloy steel: Add alloy elements to ordinary carbon steel, high-strength fasteners and add special function steels, such as 35.40CrMo, SCM435.

10B38SCM435CrMo alloy steel is mainly used for aromatic screw, the main components are C, Si, Mn, P, s, Cr, mo.