Description:1. Application - Fit for all kinds of DIY, leather crafts, clothing making, or as a fastener to connect two objects. Such as thin photo albums, leather bags, wooden board connections, etc.2. Installation - Make a hole between 0.5-1mm larger than the diameter of the female rod, put the screw and nut on both sides of the locked object, and select the appropriate tool to lock it.3. Notice - The thickness of the object which is locked, must be less than the length of the screw rod + nut rod, otherwise, it will not be able to tighten.4. Advantage - Precision mechanical thread, made of carbon steel material, black powder coating, high hardness.Specification:Product Name: Screw PostMaterial: Carbon Steel, Black Powder CoatedMain Color: BlackScrew Head Diameter: 12.8mm / 0.5"Under Head Size(Female): 8 x 15mm / 0.24" x 0.59"(D*L)Under Head Size(Male): M6 x 40mm / 0.24" x 1.57"(D*L)Fit Hole Diameter: 8mm / 0.31"Hex Socket Width: 4mm / 0.16"Applicable Thickness of Locked Object: 42-49mmWeight: 136gPackage Content: 10 Sets x Screw Post