When people buy Locks, they are generally worried that they are not durable or will rust or oxidize soon. This problem is related to the use of materials and surface treatment.
From a durable point of view, the best material should be stainless steel, especially as a surface material, the brighter the more used. Its strength is good, corrosion resistance is strong, color is invariable. However, there are many kinds of stainless steel, mainly including ferrite and austenite. Ferritic stainless steel is magnetic, commonly known as stainless iron. It takes a long time and will rust in bad environment. Only austenitic stainless steel will not rust. The identification method is very simple. One test with a magnet can identify it.
Copper is one of the most widely used lock materials, which has good mechanical properties, corrosion resistance and processing performance, and bright color, especially for copper forged handles and other lock trimmings, with flat surface, good density, no pores and sand holes. Both firm and rust proof, can be used to plating 24 K gold or sand gold and other surface treatment, it is magnificent, noble and generous, to people's home to add many colors.
Zinc alloy material, its strength and rust resistance is much worse, but its advantage is easy to make complex pattern parts, especially pressure casting. The locks with more complex patterns seen on the market are likely to be made of zinc alloy. Consumers should carefully identify them.
Iron and steel, good strength, low cost, but easy to rust, generally used as internal structural materials of locks, not as external decorative parts.
Aluminum or aluminum alloy, common aluminum alloy (except for Aerospace) is soft and light, with lower material strength, but easy to process and form.
II. Surface treatment
Surface treatment generally refers to the use of metal electrodeposition (commonly known as electroplating), coating (known as spraying), chemical oxidation (coloring) or other processing methods to cover or form a protective film on the surface of parts. The film is mainly used for anti-corrosion, but also to increase the beauty and durability of products, which is an important factor to directly measure the quality of products. The commonly used methods to measure surface treatment are: thickness measurement for covering layer, combined force inspection, salt spray and humidity test, appearance inspection, etc. The coating shall be subject to adhesion, hardness, moisture test and appearance inspection.
3、 Introduction to the new standard of door lock in China
China's new door lock standard was issued in June 2000 and implemented in October 2000. There are 4 national standards for the original door lock products. (including gb8385-97 external door lock, gb8386-87 bullet core door lock, gb8387 blade core door lock and gb8388-87 spherical door lock were respectively transformed into QB / t3837-1999, QB / t3838-1999, QB / t3839-1999 and QB / t3840-1999) and issued and implemented in 1988. However, with the continuous development of market economy, the door lock products have changed a lot. The product variety is constantly rich and the quality level is constantly improving. The original national standards and professional standards are far from meeting the requirements of door lock quality and technology in the new situation. In particular, China's accession to the WTO is imminent, economic globalization is imperative, and the level and quality of China's door lock products must be improved. In order to connect with the world, to narrow the gap with the developed countries, to eliminate trade barriers, to increase export earnings, to promote the development of China's lock industry, to participate in international competition. Therefore, the original door lock standard must be revised. The National Light Industry Bureau and the national daily hardware Standardization Center issued a notice to revise the original four door lock standards. The original spring door lock (sg205-80) and the external double tongue door lock (gb8385-87) are combined, and the double button (tiger) door lock is added to become the standard of the external door lock. The light industry standard QB implemented at present is the revised new standard.
The revision principle of the new standard is: on the basis of the original standard, it can only be raised, not lowered. We should fundamentally reverse the backward situation of low-grade products, low prices and poor technical level in China, adopt the policy of careful study and differentiated treatment, and revise it in light of China's actual situation. In the process of revision, the advanced foreign standards such as American ANSI (American national standard), British BS (British national standard) and JIS (Japanese industrial standard) are used as the basis. At the same time, according to the requirements of national laws and regulations, combined with the actual situation of the product, in the process of standard revision, according to different needs, the classification provisions are made. The external door locks and spherical door locks are divided into two categories, i.e. class A and class B, which basically distinguish the differences between high-grade villas, apartments, commercial houses and unit houses.
The requirements of the newly revised standard are higher than those of the original one. The main indexes of class a products of exterior door locks reach the level of class B in bs5872, which is higher than the original standard in China, but lower than class B products in bs5872 (Note: Class B products in British BS standard are higher than class a products), and the main indexes of class a products in spherical door locks are close to the level of class II locks in ANSI / bama.a156.2-1996. The main index of class B product is close to the level of class III lock in ANSI / BA and a.a156.2-1996, and it is much higher than the original standard in China. Therefore, the revised new door lock standards QB / t2473-2000, QB / t2475-2000, QB / t2474-2000 and QB / t2476-2000 are higher than the original standards.
4、 Lock common sense column
Consider before purchasing
Consumers should consider the following before purchasing locks.
1. Place used and its importance.
That is to say, it is considered to be used on the street gate, hall door, room, bathroom or passageway, so as to select products suitable for the required functions.
2. Use environment, conditions and requirements.
Consider the advantages and disadvantages of the use environment, such as dry humidity, door structure, thickness, left or right door, inside or outside door