Cross recessed half countersunk head screw full thread (cross)

　　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: trivalent color zinc (5um-48/72h)

　　Surface treatment content: Color zinc plating refers to the process of treating a galvanized layer in a chromate solution to obtain a rainbow colored passivation film. Its structure is generally considered to be a complex mixture composed of basic chromium chromate, basic zinc chromate, chromium chromate, zinc chromate, and oxides of zinc and chromium. The galvanized layer is passivated to a rainbow color. Environmentally friendly, neutral salt spray test with no white rust after 48 hours and no red rust after 72 hours