Description:1. Feature: Button head machine screws, hex socket drive. Metric machine screws for universal use.2. Material: Made of alloy steel, the blackened surface treatment is anti-oxidation, wear-resistant, anti-corrosion, and it is smoother to use.3. Application: Widely used where fastening is required, the assembly and maintenance of households, machine tools, construction, and DIY projects. Such as household hardware, electrical products, mechanical equipment products, etc.Specification:Product Name: Hex Socket Button Head BoltsMaterial: Alloy SteelSurface Treatment: BlackeningPerformance Grade: 12.9Color: BlackDimension: M6 x 40mmRod Length(Under Head): 40mm / 1.57"Pitch: 1mm / 0.04"Inner Hex Width: 4mm / 0.16"Screw Head Size: 10.3 x 3.5mm / 0.41" x 0.14"(Dia.*Thickness)Package Content:25pcs x Hex Socket Bolts