Double headed screw A-type thick rod

　　Strength: 10.9 Material: carbon steel, alloy steel

　　Material: 40Cr

　　Material description: C 0.37-0.44, Mn0.50-0.80，Si0.17-0.37，Cr0.80-1.10，Cu≤0.30，Ni≤0.30，P≤0.035，S≤0.035， It is similar to American grade 5140, Japanese grade SCr440, German, British, and French 42Cr4, and ISO standard 41Cr4

　　Surface treatment: Dacromet (silver gray 8 μ m-480h)

　　Surface treatment content: Silver gray Dacromet, 8 μ m after film, no red rust after 480 hours of salt spray test, friction coefficient 0.08-0.14

　　Risk reminder: Products with fastener performance level ≥ 10.9 may have a risk of hydrogen embrittlement during electroplating