（1） 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.
1. Low carbon steel C% ≤ 0.25% is commonly referred to as A3 steel in China. It is basically called 1008101510181022 in foreign countries. It is mainly used for products without hardness requirements such as grade 4.8 bolts, grade 4 nuts, small screws, etc. (Note: drill tail screws are mainly made of 1022 material).
2. Medium carbon steel 0.25% 0.45%. Currently, it is basically not used in the market.
3. 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. Aromatic screws mainly use SCM435 chromium molybdenum alloy steel, with the main components of C, Si, Mn, P, S, Cr, and Mo.
（2） Stainless steel. Performance grade: 45, 50, 60, 70, 80 mainly composed of austenite (18% Cr, 8% Ni) with good heat resistance, corrosion resistance, and weldability.
A1, A2, A4 martensite, 13% Cr have poor corrosion resistance, high strength, and good wear resistance. C1, C2, C4 ferritic stainless steel. 18% Cr has good upsetting property and stronger corrosion resistance than martensite. Currently, the main imported materials on the market are Japanese products.
By level, it is mainly divided into SUS302, SUS304, and SUS316.
（3） Copper. The commonly used material is brass zinc copper alloy. On the market, H62, H65, and H68 copper are mainly used as standard parts. Disc elements used in carbon steel products: serial number and type: materials available: grade 1 4.8 hexagon screws 1008K 1010 1015K 2 6.8 hexagon screws.
Bolt standard:
National Standard for Hexagon Bolt GB/T5782-86
The standard specifies hexagon head bolts with thread specifications of M3~M64, Grade A and B, and Grade A is used for bolts with D<=24 and L<=10D or L<=150mm (whichever is smaller); Class B is used for bolts with D>24 or L>10D or L>150, whichever is less.
Outer hexagon bolt size:
External hexagonal bolt standard: DIN ANSI BS GB
Material: stainless steel or carbon steel
Diameter: 5mm~20mm, 1/4 ″~3/4 ″
Length: 8mm~200mm, 5/16 ″~8 ″
Thread: Metric, Coarse, Fine, Inch
Mechanical properties: 4.8, 5.8, 6.8, 8.8, 9.8, 10.9, 12.9
Surface treatment: natural color, zinc plated, blackened, nickel plated
Post time: Mar-24-2023