Features: -340pcs Star lock washers with 100mm diameter internal teeth in 7 sizes, M3 M4 M5 M6 M8 M10 M12, meet your your different needs. -Manufactured made of high quality steel Made of 65Manganese metal, anti-corrosion and durable. -Provides spring force, sturdy grip, creates more friction and resistance to friction. the rotation. -Used in machinery, furniture, electrical appliances, electronic equipment, cars and industrial production of shock absorption and insulation. -All lock washers are stored in a clear plastic sorting box with data sheet, easy identification and storage. Specifications: Washer Type: Star Washer Material: 65Manganese Steel Color: Black Sizes: M3 M4 M5 M6 M8 M10 M12 Weight: 200g Quantity: 340 pcs Package included: M3 x 60 pcs M4 x 60pcs M5 x 60pcs M6 x 50pcs M8 x 50pcs M10 x 40pcs M12 x 20pcs Warm Tip: 1)Keep small items out of reach children. 2)Shocks during transportation may confuse small items.