Package content 280 pieces of lock washer 1. Utility The lock washer is designed for quick fixing and repairing by using spring force to secure the washer closely to the base, enhancing the friction and rotational resistance between the bolt thread and nut or base thread. 2. High quality material Lock washers are made from strong and durable 65 manganese steel, offering resistance to deformation, abrasion, and corrosion. 3. Multiple sizes Quick Lock Washers come in 7 commonly used sizes: M3, M4, M5, M6, M8, M10, and M12, allowing you to select the appropriate size based on your requirements. 4. Wide application Fixed washers are extensively utilized in machinery equipment, lawn mowers, engines, cars, trucks, trailers, toys, bicycles, recreational vehicles, boats, pumps, furniture, etc. 5. Economic package This set includes 280 pieces of black steel lock washers stored in a plastic box, with each size neatly separated for easy selection and storage. The 7 sizes cater to your various needs.