At present, the standard parts on the market mainly include carbon steel, stainless steel and copper.

1. Carbon steel. We distinguish low carbon steel, medium carbon steel and high carbon steel and alloy steel by the content of carbon in carbon steel material.

1, low carbon steel C%≤0.25% domestic usually called A3 steel. It is basically called 1008,1015,1018,1022 and so on. Mainly used for 4.8 class bolts and 4 class nuts, small screws and other products without hardness requirements. (Note: Drilling nails mainly use 1022 material.)

2, medium carbon steel 0.25%

3, high carbon steel C%>0.45%. At present, there is little use in the market

4, alloy steel: Add alloying elements to carbon steel to increase some special properties of steel: such as 35, 40 chromium molybdenum, SCM435, 10B38. High-quality 12.9 grade screws mainly use SCM435 chrome-molybdenum alloy steel, the main components are C, Si, Mn, P, S, Cr, Mo.

Two, stainless steel. It is mainly divided into austenite, martensite and ferrite.

1, austenite (18%Cr, 8%Ni) good heat resistance, good corrosion resistance, good weldability. The main grades are SUS302, SUS304, and SUS316.

2, martensite (13%Cr) poor corrosion resistance, high strength, good wear resistance.

3, ferritic stainless steel C1, C2, C4, 18%Cr upsettability is better, corrosion resistance is stronger than martensite.

3. Copper. On the market, H59 and H62 copper are mainly used as standard parts.