Materials and surface treatment - Corrosion-resistant 304 stainless steel ensures durability in humid or indoor environments. SPECIFICATION:Product Name: Pan Head Self Tapping Screws Kit Set for Metal, WoodThread Diameter: M6(Thread Dia x Pitch)Screw Length:M6x12,M6x16,M6x20,M6x25,M6x30,M6x40Surface Treatments: PlainMaterial: 304 Stainless steelQUANTITY INCLUDED - 135Pcs 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.