About this item Protective function: flat washers can distribute a load and prevent damage to the surface to be repaired. And isolate the screws from the surface. Longer machine life. Easy to find: The pack contains 200 flat washers and lock washers in a transparent PP box. You can clearly see the copper sump plug washer through the compartmentalized plastic housing. Feature - Made of copper. Good electrical conductivity and thermal conductivity. Melting point up to 1083. Wide applications: perfect for most types of engines, whether automotive, marine, generator, machinery and plant . Also great for sump plugs, water, fuel and hydraulic fittings. 9 Sizes - Contains 9 sizes of the most commonly used washers. Type: M5*9*1mm, M6*10*1mm, M6*12*1mm, M8*12*1mm, M8*14*1mm, M10*14*1mm, M12*16*1mm, M12*18*1, 5mm, M14*18*1mm.