Hollow cross composite groove pan head expansion bol

　　Strength: 4.8 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: Blue white zinc

　　Surface treatment content: Function: Rust prevention, decoration, and improved corrosion resistance Applicable materials: Various types of steel parts Coating appearance: Blue white Execution standard: ASTM-B633-98 Not environmentally friendly