Lock ring with screw

　　Strength: No grade requirement Material: Carbon steel, alloy steel

　　Material: Low carbon steel

　　Material description: C 0.14-0.22, Mn0.3-0.650,Si≤0.30,Cr≤0.30,Cu≤0.30,P≤0.045,S≤0.05，Ni≤0.3,, It is similar to American grade 1020, Japanese grade SS400, German, British, and French S235JR, and ISO standard E235

　　Surface treatment: Blackening (without quenching)

　　Surface treatment content: Blackening is a common method of metal heat treatment, which is to produce a layer of oxide film on the metal surface to isolate air and achieve the purpose of rust prevention