680 Pieces in 7 Sizes: 680 pieces internal tooth star lock washer in 7 sizes: M3 x 9 mm, M4 x 12 mm, M5 x 12 mm, M6 x 14 mm, M8 x 18 mm, M10 x 20 mm, M12 x 25 mm, enough to meet your usual needs. Sturdy and Durable: Starlock washers made of high quality 65 manganese steel, black oxide coating prevents oxidation and aging, provides good corrosion resistance and high temperature performance. Excellent Locking Function: The lock washer exerts spring force between the head of the fasteners and the substrate, creating more friction and resistance to rotation, ideal for quick repairs and making a repair. Wide Application: Widely used in machinery, furniture, electrical appliances, electronic equipment, cars, sports equipment and industrial production of shock absorption and insulation. Portable Tools: All star washers are stored in a clear plastic sorting box with a specification sheet, you can quickly find what you need, easy identification and storage. Delivery Quantity: 1 setluckymeet