What are the current hex head bolt materials?


At present, the hexagon socket screws on the market mai […]

At present, the hexagon socket screws 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 as well as alloy steel with carbon content in carbon steel.
1, low carbon steel C% ≤ 0.25% domestically known as A3 steel. Foreign countries are basically called 1008, 1015, 1018, 1022 and so on. It is mainly used for products with no hardness requirements such as 4.8 bolts, 4 grade nuts, small screws (Note: 1022 material is mainly used for drilling tail nails).
2. Medium carbon steel is 0.25% and 0.45%. Currently it is basically not used in the market.
3. Alloy steel: Add alloying elements to the carbon steel to increase some special properties of the steel: such as 35, 40 chromium molybdenum, SCM435, 10B38. The main screw is SCM435 chrome-molybdenum alloy steel. The main components are C, Si, Mn, P, S, Cr and Mo.
(2) Stainless steel. Performance grade: 45, 50, 60, 70, 80 Mainly divided into austenite (18% Cr, 8% Ni), good heat resistance, good corrosion resistance and good weldability. A1, A2, A4 Martensite, 13% Cr has poor corrosion resistance, high strength and good wear resistance. C1, C2, C4 ferritic stainless steel. 18%Cr is better forging and corrosion resistance is stronger than martensite. Currently, the imported materials on the market are mainly Japanese products. Mainly divided into SUS302, SUS304, and SUS316 by level.
(3) Copper. Commonly used materials are brass zinc-copper alloy. The market mainly uses H62, H65 and H68 copper as standard parts. The disk used for carbon steel products: serial number Material of choice 1 4.8 hex screw 1008K 1010 1015K 2 6.8 hex screw.