1. Screws are mainly made of carbon steel, stainless steel and copper. (1) Carbon steel: low carbon steel, medium carbon steel, high carbon steel, alloy steel.
1. Low carbon steel: A3 steel (Q235 high wire), SWRCH6A, 8A (ML08AL), 15A, 18A (1018), 22A (1022). (Mainly used for grade 4.8 bolts, grade 4 nuts, small screws and other products without hardness requirements.)
2. Medium carbon steel: ①It is usually called No. 35 and No. 45 steel in China. ②It is basically called 1035 and SWRCH35K abroad. (Mainly used for grade 8 nuts, grade 8.8 bolts, grade 8.8 inner hexagon products.)
3. High carbon steel: C%>0.45%, basically not used in the market.
4. Alloy steel: ① In addition to carbon, it also contains some other alloying elements (such as silicon, manganese, chromium, nickel, vanadium, molybdenum, etc.). For grade 12.9 screws, chromium-molybdenum alloy steel, such as SCM435, is mainly used. ②Alloying elements are added to ordinary carbon steel to increase some special properties of steel: 35CrMo (SCM345), 35CrMo (SCM440). ③Fangsheng screws use: SCM435 chromium-molybdenum alloy steel. (Main components: C, Si, Mn, P, S, Cr, Mo). (2) Stainless steel: ① Mainly divided into martensitic stainless steel, austenitic stainless steel, ferritic stainless steel and so on. ②Performance grade: 45, 50, 60, 70, 80 (usually SUS200 series, SUS302, SUS304, SUS316, SUS410, etc.) ③Imported materials are mainly Japanese products. (Mainly divided into SUS302, SUS304, SUS316 according to the level) (3) Copper: Commonly used materials are brass and zinc-copper alloy. (Mainly use H62, H65, H68 copper as standard parts.) Selection of carbon steel screw material 2. Specific summary of screw wire 1. The main chemical components in steel are: C, Mn, P, S, Si, Cu, Al, Among them, the lower the content of Al and Cu, the better. Classification of commonly used screws and wires III. Detailed types of wires 1. Wire: galvanized wire, normal wire, high-speed wire, iron wire, spring steel wire, coiled wire (strip), welded wire, excellent wire, hard wire, plain carbon round steel, Iron wire, cold drawn wire 2. Special steel: carbon structure steel, composite steel, bearing steel, die steel, spring steel, gear steel, carbon steel, low alloy steel, low carbon steel 3. Stainless steel: stainless wire , Stainless steel plate, stainless coil, stainless steel wire, stainless steel tube, stainless seamless tube, stainless welded tube, stainless steel strip, stainless steel angle, stainless hexagonal steel, stainless steel coil, stainless steel rod, stainless steel hot-rolled Steel strip, stainless steel and heat-resistant steel cold-rolled steel strip, stainless steel cold-rolled steel for springs 4. Non-ferrous metals: copper, aluminum, lead, zinc, tin, nickel, cobalt, antimony, bismuth, magnesium, cadmium, titanium, rare and precious metals .
