Product Package: 280 pieces of lock washers Utility: The lock washer is designed for quick fixing and repairing. It applies spring force between the fixing head and the base body, ensuring tight contact and increased friction to prevent loosening due to vibration. High-Quality Material: Made from 65 manganese steel, these lock washers are strong, durable, resistant to deformation, wear, and corrosion. Multiple Sizes: Includes 7 commonly used metric sizes: M3, M4, M5, M6, M8, M10, M12. Choose the appropriate size based on your application needs. Wide Application: Suitable for use in machinery, lawn mowers, engines, automobiles, trucks, trailers, bicycles, recreational vehicles, boats, pumps, furniture, and other equipment. Economic Package: 280 pieces of black steel lock washers organized in a plastic storage box with separate compartments for each size, allowing for easy access and organization. The variety of sizes included meets a wide range of fastening requirements.