Material knowledge of screws


2023-05-29 10:00

At present, there are three main materials of standard parts in the market: carbon steel, stainless steel, and copper.
One carbon steel. We distinguish low carbon steel, medium carbon steel, high carbon steel, and alloy steel based on the carbon content in carbon steel materials.
Low carbon steel with C% ≤ 0.25% is commonly referred to as A3 steel in China. Basically referred to as 1008101510181022 in foreign countries. Mainly used for products without hardness requirements such as grade 4.8 bolts, grade 4 nuts, and small screws. (Note: The drilling tail nail is mainly made of 1022 material.)
2% carbon steel 0.25%
3. High carbon steel C%>0.45%. Basically not used in the market
4 alloy steel: Adding alloy elements to plain carbon steel increases some special properties of the steel, such as 35, 40 chromium molybdenum, SCM435, and 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, with main components including C, Si, Mn, P, S, Cr, and Mo.
Two stainless steels. Performance level: 45, 50, 60, 70, 80
1. The main components of austenite (18% Cr, 8% Ni) have good heat resistance, corrosion resistance, and weldability. A1, A2, A4
2 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 performance and corrosion resistance than martensite. The main imported materials in the market are from Japan. Mainly divided into SUS302, SUS304, and SUS316 by level.
Three copper. The commonly used material is brass... zinc copper alloy. H62, H65, and H68 copper are mainly used as standard parts in the market.

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