Hexagonal head bolt full thread

　　Strength: 8.8 Material: carbon steel, alloy steel

　　Material: medium carbon steel

　　Material description: C 0.32-0.39, Mn0.50-0.80，Si0.17-0.37，Cr≤0.25，Cu≤0.25，Ni≤0.30，P≤0.035，S≤0.035， It is similar to American grade 1035, Japanese grade S35C, German, English, and French grade C35, and ISO standard C35E4

　　Surface treatment: Blackening (quenching)

　　Surface treatment content: Blackening is a common method of metal heat treatment, which is to create a layer of oxide film on the metal surface to isolate air and achieve the purpose of rust prevention. When the appearance requirements are not high, blackening treatment can be used, and the surface of steel parts can be blackened, also known as bluing.