Standard parts on the market mainly include carbon steel, stainless steel, and copper.
       (1) Carbon steel We distinguish low carbon steel, medium carbon steel, high carbon steel and alloy steel by the carbon content in carbon steel materials.
       1. Low carbon steel C%≤0.25% is usually called A3 steel in China. Foreign countries are basically called 1008, 1015, 1018, 1022 and so on. Mainly used for grade 4.8 bolts and grade 4 nuts, small screws and other products without hardness requirements. (Note: Drilling screws are mainly made of 1022 material.)
       2. Medium carbon steel 0.25%.
       3. High carbon steel C%>0.45%. It is basically not used in the market at present.
       4. Alloy steel: Add alloy elements to ordinary carbon steel to increase some special properties of steel: such as 35, 40 chromium molybdenum, SCM435, 10B38.
       (2) Stainless steel performance grades: 45, 50, 60, 70, 80.
       Mainly divided into austenite (18%Cr, 8%Ni) has good heat resistance, good corrosion resistance and good weldability. A1,A2,A4. Martensite and 13%Cr have poor corrosion resistance, high strength and good wear resistance. C1, C2, C4 ferritic stainless steel. 18%Cr has better upsetting forgeability and stronger corrosion resistance than martensite. At present, imported materials on the market are mainly Japanese products. According to the level, it is mainly divided into SUS302, SUS304 and SUS316.
       (3) Commonly used materials for copper are brass and zinc-copper alloy. H62, H65 and H68 copper are mainly used as standard parts in the market.