When people buy locks, they generally worry that the locks are not durable or will not rust or oxidize on the surface for long. This problem is related to the materials used and surface treatment. From a durable point of view, the best material should be stainless steel. It has good strength and strong corrosion resistance. Copper is one of the most widely used lock materials. It has good mechanical properties, good corrosion resistance and processing performance, and has a beautiful color. Especially forged copper handles and other lock decorative parts, the surface is smooth and dense, which is firm antirust. Zinc alloy materials have much less strength and rust resistance, but their advantage is that they can be easily made into parts with complex patterns. The locks with more complicated patterns seen in the market are likely to be made of zinc alloy, and consumers should carefully identify them. Steel has better strength and lower cost, but it is easy to rust. It is generally used as the internal structure material of locks, and is not suitable for external decoration. Aluminum or aluminum alloy, ordinary aluminum alloy (except for aerospace) is soft and light, the material strength is relatively low, but it is easy to form.
Lock surface treatment refers to the use of metal electrodeposition, painting (called spraying), chemical oxidation (coloring) or other processing methods to cover or form a protective film on the surface of the part. The film mainly plays a role of anticorrosion, and at the same time increases the appearance and durability of the product, which is an important factor to directly measure the quality of the product. Common methods for measuring surface treatment are: thickness measurement of covering layer, binding force inspection, salt spray and humidity test, appearance inspection, etc. The coating is carried out by methods such as coating adhesion, hardness, humidity test and appearance inspection.