Premium MaterialThe inner teeth quick release metal washers are made of 65 manganese steel. It is sturdy and durable, no deformation, abrasion resistance and corrosion resistance. Durable for a long time. A Washers exerts spring force between the head and the substrate. Practical ToolThe self-locking washers are ideal for quick fixes and repairs. It can apply spring force between the mounting head and the substrate, making the washer hard against the substrate. For greater resistance to friction and rotation. Various SizesThe Lock Washers with 7 most common sizes. There are M3 / M4 / M5 / M6 / M8 / M10 / M12 You can choose different sizes according to your needs. Wide ApplicationWasher range widely used in many fields, e.g. Machine equipment, lawn mowers, engines, cars, trucks, trailers, toys, bicycles, RVs, boats, pumps, furniture, etc. Package IncludesThe fastener assortment kit contains 340 pieces of black color lock washer with a plastic box. Each size is individually separated in the storage box for easy selection and storage. 7 sizes of lock washers meet your different needs. Technical Data - Product Name: Lock Washer - Material: 65 Manganese Steel - Color: Black - Type: M3, 4, 5, 6, 8, 10, 12 - Thickness(M3, M4, M5, M6): 0.4mm - Thickness(M8, M10): 0.5mm - Quantity: 340pcs Size: Outer Diameter x Inner Diameter: M3: 9 x 2.7mm M4: 12 x 3.8mm M5: 14 x 4.9mm M6: 16 x 5.9mm M8: 16 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 Contains: M3: 60 M4: 60pcs M5: 60pcs M6: 50pcs M8: 50pcs M10: 40pcs M12: 20pcs Advantages: - The washers are made of 65 manganese steel, to be corrosion resistant and durable. - A Lock Washer exerts a spring force between the head and the substrate, creating more friction and resistance to rotation. - These washers come in a divided storage box ideal for storage and removal. - Are widely used in machine equipment, industrial production shock absorbing, bearings, machinery, etc.