Look at materials: Lock materials in the market are basically divided into stainless steel, copper, zinc alloy, iron steel and aluminum materials. Stainless steel has good strength, strong corrosion resistance and constant color. It is the best material for lock making. Copper is more common, mechanical property is superior, price is more expensive, high quality zinc alloy is strong and wear-resistant, corrosion resistance is very strong, easy to form, generally used to make middle lock.