About this item Protective function: flat washers can distribute a load and prevent damage to the surface to be repaired. Isolate the screws from the surface. Helps extend 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. Made of copper. Good electrical conductivity and thermal conductivity. Melting point up to 1083°C. Wide applications: suitable for most types of engines, including automotive, marine, generator, machinery, and industrial equipment. Ideal for sump plugs, water, fuel, and hydraulic fittings. 9 Sizes included: 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.