Cross recessed pan head self tapping screw and enlarged flat washer assembly (C-type)

　　Strength: surface hardening 400HV Material: carbon steel, alloy steel

　　Material: 1022

　　Material Description: Aluminum deoxidized steel Composition: C: 0.18-0.23; S：≤0.10; Mn：0.70-1.00; P：≤0.030; S：≤0.035; AL：≥0.02

　　Surface treatment: trivalent colored zinc

　　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 384H without red rust

　　Risk reminder: The hardness value of hardened steel on the surface of fasteners is ≥ 320HV, and there is a risk of hydrogen embrittlement during electroplating!