Screw wire is the raw material of screw manufacturing. Because the screw material is different, the screw strength level is different, the screw mechanical properties are different and so on. When we choose to produce screws, the production of raw. Screws are mainly carbon steel, stainless steel, copper three materials (a) carbon steel: low carbon steel, medium carbon steel, high carbon steel, alloy steel. 1, low carbon steel: A3 steel (Q235 high line), SWRCH6A, 8A (ML08AL), 15A, 18A (1018), 22A (1022). (Mainly used for Class 4.8 bolts, class 4 nuts, small screws and other products without hardness requirements.) 2, medium carbon steel: ① domestic usually known as 35, 45 steel. ② It is basically called 1035 and SWRCH35K abroad. (Mainly used for Class 8 nuts, 8.8 bolts and 8.8 hex socket products.) 3, high carbon steel: C%>0.45%, basically not used in the market. 4, alloy steel: ① refers to the steel containing carbon, but also contains some other alloy elements (such as silicon, manganese, chromium, nickel, vanadium, molybdenum, etc.), for 12.9 level screw mainly use chrome-molybdenum alloy steel, such as SCM435. ② Alloying elements are added to general carbon steel to increase some special properties of steel: 35CrMo (SCM345), 35CrMo (SCM440). ③ Aromatic screw use: SCM435 chrome-molybdenum alloy steel. (Main components: C, Si, Mn, P, S, Cr, Mo). MAIN PRODUCE SIZE: 18A (1018), 22A (1022)