product description:Material: Manganese steelColour: BlackBox size: 170*100*25mmWeight: 200gNumber of products: 280Model: M3/M4/M5/M6/M8/M10/M12Features:1. The lock washer exerts an elastic force between the head of the fastener and the substrate to generate greater friction and rotational resistance2. Widely used in mechanical equipment, shock absorption and insulation in industrial productionPackage list:40xM3 ket40xM4 ket40xM5 ket50xM6 ket50xM8 ket40xM10 ket20 x M12 ket