The materials of nuts and bolts are the same. The following is a detailed explanation of the bolt materials:

The material of the bolt may be the hardness and strength of the bolt when it has a special purpose. When choosing a bolt, the material problem should be considered. At present, the standard bolt materials on the market mainly include carbon steel bolts, stainless steel bolts, and copper bolts.

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

1. Low carbon steel C% ≤ 0.25% is usually called A3 steel in China. Foreign countries are basically called 1008, 1015, 1018, 1022, etc. Mainly used for 4.8 grade bolts, 4 grade nuts, small screws and other products without hardness requirements. (Note: Drill tail nails are mainly made of 1022 material.)

2. Medium carbon steel 0.25% < C% ≤ 0.45% is usually called No. 35 and No. 45 steel in China, and basically 1035, CH38F, 1039, 40ACR in foreign countries. Mainly used for grade 8 nuts, grade 8.8 bolts and grade 8.8 hexagon products.

3. High carbon steel C% > 0.45%. It is basically not used in the market at present

4. Alloy steel: Alloying elements are added to ordinary carbon steel to increase some special properties of steel: such as 35, 40 chromium molybdenum, SCM435, 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, the main components are C, Si, Mn, P, S, Cr, Mo.

(2) Stainless steel. Performance grade: 45, 50, 60, 70, 80

Mainly divided into austenite (18% Cr, 8% Ni) with 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 and forging properties and stronger corrosion resistance than martensite. At present, imported materials on the market are mainly Japanese products. Mainly divided into SUS302, SUS304, SUS316 by grade.

(3) Copper. Commonly used