High-quality material The internal teeth quick release metal washer is made of 65 manganese steel, which is strong, durable, non-deformable, wear-resistant, and corrosion-resistant. Star lock washers apply a spring force between the head and the base plate. Self-locking washers are ideal for quick maintenance and repairs. They exert a spring force between the mounting head and the base plate, helping to hold the seal in place. High friction and resistance to rotation. Various sizes Lock washers are available in 7 common sizes: M3, M4, M5, M6, M8, M10, and M12. Choose the size that meets your needs. Wide application Washers are widely used in mechanical equipment, lawn mowers, engines, cars, trucks, trailers, toys, bicycles, RVs, boats, water pumps, furniture, and more. Package included Fastener combo kit contains 340 black lock washers and a plastic storage box. Each size is stored separately for easy selection and organization. 7 sizes of clamp washers to meet various requirements. Technical data - Product name: Lock washer - Material: 65 manganese steel - Color: Black - Sizes: M3, M4, M5, M6, M8, M10, M12 - Thickness: M3, M4, M5, M6: 0.4mm; M8, M10: 0.5mm - Quantity: 340 pieces - Dimensions (OD x ID): M3: 9 x 2.7mm M4: 12 x 3.8mm M5: 12 x 4.9mm M6: 14 x 5.9mm M8: 18 x 7.9mm M10: 20 x 9.3mm - Height: M3: 1.4mm M4: 1.5mm M5: 1.5mm M6: 2.1mm M8: 2.3mm M10: 2.3mm - Package contents: M3: 60 pieces M4: 60 pieces M5: 60 pieces M6: 50 pieces M8: 50 pieces M10: 40 pieces M12: 20 pieces Advantages: - Made of 65 manganese steel for durability and corrosion resistance. - Lock washers provide spring force between the head and base plate, increasing friction and resistance to rotation. - Comes with a compartmentalized storage box for convenient organization and access. - Suitable for use in mechanical equipment, industrial applications, bearings, machinery, and more.