【Premium material 】The 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 Starlock washers exert a spring force between the head and the substrate. 【Handy tool 】Self-locking washers are ideal for quick fixes and repairs. It can apply a spring force between the mounting head and the substrate, which makes the washer hard against the substrate. For greater resistance to friction and rotation. 【Different sizes 】Lock Washers with 7 most common sizes. There are M3 / M4 / M5 / M6 / M8 / M10 / M12 Starlock. You can choose different sizes according to your needs. 【Wide application 】Range of washers widely used in many areas e.g. machine equipment, lawn mowers, motors, cars, trucks, trailers, toys, bicycles, RVs, boats, pumps, furniture, etc. 【The package includes 】The fastener assortment kit contains 340 pieces of lock washer in black color with a plastic box. Each size is individually separated in the storage box for easy selection and storage. 7 sizes of clamp 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): 0.4 mm - Thickness (M8, M10): 0.5 mm - Quantity: 340 pcs 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 pieces M4: 60 pieces M5: 60 pieces M6: 50 pieces M8: 50 pieces M10: 40 pieces M12: 20 pieces Advantages: - The washers are made of 65 manganese steel, to be corrosion resistant and durable. - A Locking 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 machinery equipment, production industrial shock absorbing, bearings, machinery, etc.