Product Details: Color: Black Material: Carbon Steel Thread Size: M2x6/8/10mm, M3x8/12/16/20mm, M4x12/16/20/30mm, M5x40mm Screw Expansion Tube Size: 6mm x 30mm/0.24" x 1.18"(D*L) Package Content:505pcs x Self Tapping Screws Kit(12 sizes in M2 M3 M4 M5)20pcs x Screw Expansion Tube Material - These screws are constructed with carbon steel material which is finished with black oxide coating providing extra protection against rust and corrosion, offering excellent strength and durability, being oxide-resistant, wear-resistant, and not easy to deform and break.Feature - Self-tapping screws offer convenience and efficiency, with a sharp, pointed tip allowing for quick and reliable fastening without the need for pre-drilling or additional hardware. What's more, the cross-drive screws feature a countersunk head design to sit flush with the surface they are being driven into.Application - Flat head screws are great replacement parts and construction fasteners for machinery, industry, manufacturing applications, household appliances, furniture, woodworking, DIY projects, etc. Suitable for use in a variety of materials, such as plastics, wood, metal, etc.Notice - The wood screws are packed in a durable box, to avoid making a mess, the box is clearly labeled so that you can quickly identify the size you need by the label.