People who buy the material of the lock usually worry that the lock is not durable, or the surface will rust or oxidize soon. This problem is related to the use of materials and surface treatment. From the standpoint of durability, the best material is stainless steel, especially as the surface material is getting lighter and lighter. Its strength, corrosion resistance and color remain unchanged. There are also various stainless steels, which can be divided into ferrite and austenite. Ferrite stainless steel is magnetic, commonly known as stainless iron. After a long time, it will rust in a bad environment. Only austenitic stainless steel gun lock steel will rust. The identification method is very simple. Try to identify the magnet. Copper is one of the most widely used lock materials. It has good mechanical properties, corrosion resistance and processing performance, and beautiful colors, especially forged brass handles and lock trims, surface roughness, density, and no holes ,trachoma. It is strong and rust-proof, and can be used for surface treatment such as 24K gold plating or gold powder, which looks magnificent and elegant, and adds a lot of color to people's homes. The strength and rust resistance of zinc alloy materials are more backward, but its advantage is that it is easy to make parts into complex patterns, especially die castings. The zinc alloy lock patterns seen on the market are more complicated, and consumers should carefully identify them. Steel has good strength, low cost, and is not easy to rust. The materials generally used for the internal structure of locks are not suitable for external decoration. Aluminum or aluminum alloy, aluminum is soft and light, stronger than the substrate, but easy to shape.

        There are two kinds of surface treatments. Surface treatment means to lock the cable on the surface of the part or form a protective film under the action of metal and deposition, coating, chemical oxidation or other processing methods. The film mainly plays a role in anti-corrosion, but also increases the appearance and durability, which is an important factor to directly measure the quality of the product. Common methods for measuring surface treatment: covering layer thickness measurement, bonding force inspection, salt spray and humidity test, visual inspection. Coating adhesion, hardness, humidity test and visual inspection method.