Materials and surface treatment - Exceeds stainless steel in tensile strength, designed for fastening in machinery. SPECIFICATION:Product Name: Pan Head Self Tapping Screws Kit Set for Metal, WoodThread Diameter: M3(Thread Dia x Pitch)Screw Length:M3x6,M3x8,M3x10,M3x12,M3x16,M3x18,M3x20Surface Treatments: Black OxideMaterial: Carbon SteelQUANTITY INCLUDED - 500Pcs x Pan Head Self Tapping ScrewsADVANTAGE - Requires pre-drilling in metal substrates, optimized for soft metals like aluminum/copper to eliminate thread stripping. Also widely used in wood, furniture, and other purposes.DESIGN - Deep cross recess minimizes cam-out, ensuring stable engagement with screwdrivers for precise installation. Balances performance and affordability, suitable for furniture assembly, electronic device mounting, and DIY projects.