Function: 1. Carbon Steel Material: Self-tapping screws made of black carbon steel are durable, resistant to wear and corrosion. 2. With washer included: The self-tapping screw comes with a washer that is stronger and harder to loosen. 3. Application: Self-tapping screws are suitable for steel, aluminum, wooden, plastic and other similar materials. Self-drilling does not require pre-drilling. 4. Applicable Industry: This is a self-tapping screw with washer, which is widely used in industry. 5. Different Specifications: This set of self-tapping screws has different specifications to meet your different needs. Specification: Item Type: Self Tapping Screw Set Material: Black carbon steel Technical data: 40 pieces M5 x 12 25 pieces M4 x 12 50 pieces M3,5 x 16 60 pieces M3,5 x 12 35 pieces M4 x 10 35 pcs. M3,5 x 20 35 pieces M4 x 20 60 pieces M3 x 10 40 pieces M4 x 16 List of packages: 380 x Round head self-tapping screw with washer