锁具的材料及表面处理

One: Material Selection

When purchasing locks, people often worry about durability and the possibility of rust or oxidation on the surface. This issue is closely related to the material used and the surface treatment process.

In terms of durability, stainless steel is considered the best material, especially when used as the outer layer. The more it is used, the shinier it becomes. It has excellent strength, strong corrosion resistance, and maintains its color well. However, not all stainless steel is the same. It can be mainly divided into ferritic and austenitic types. Ferritic stainless steel has magnetic properties and is commonly known as "stainless iron." Over time, under poor environmental conditions, it may still rust. Only austenitic stainless steel is truly rust-proof. A simple way to distinguish them is by using a magnet—ferritic stainless steel will be attracted, while austenitic stainless steel won't be.

Copper is one of the most widely used materials for lock production. It has excellent mechanical properties, good corrosion resistance, and excellent processing capabilities. Its lustrous appearance makes it particularly suitable for decorative components like handles and other embellishments. Copper-cast handles and other decorative parts are smooth, dense, without pores or air bubbles. They are both sturdy and rust-resistant. Additionally, copper components can be plated with 24K gold or sand gold finishes, adding an elegant and luxurious touch to any home.

Zinc alloy materials have much lower strength and rust resistance compared to other materials, but they excel in forming complex patterns, especially through pressure casting. Many intricate-looking locks on the market are likely made from zinc alloy. Consumers should carefully examine these products before purchase.

Steel has good strength and low cost but is prone to rusting. It is typically used for internal structural components rather than external decorative parts.

Aluminum or aluminum alloys are soft and lightweight, making them easy to shape. However, their material strength is relatively low.

Two: Surface Treatment

Surface treatment refers to the process of applying a protective film on the part's surface through methods such as metal electro-deposition (commonly known as electroplating), painting (spraying), chemical oxidation (coloring), or other techniques. This layer primarily serves a protective function against corrosion while also enhancing aesthetics and product longevity. It is a critical factor in determining product quality. Common methods to evaluate surface treatment include measuring coating thickness, checking adhesion, conducting salt spray and humidity tests, and inspecting appearance. For coatings, tests such as adhesion, hardness, humidity tests, and appearance checks are performed.

New Standards for Door Locks in China

The new national standards for door locks were released in June 2000 and implemented in October 2000. The original four national standards for door locks (including GB8385-97 "External Door Locks"; GB8386-87 "Pin Tumbler Core Locks"; GB8387 "Leaf Core Locks," and GB8388-87 "Ball Locks") were converted into QB/T3837-1999, QB/T3838-1999, QB/T3839-1999, and QB/T3840-1999 respectively in March 1999. These standards were originally published in 1988. However, with the rapid development of the market economy, significant changes occurred in door lock products. The variety of products expanded, and the quality improved. The original national and professional standards could no longer meet the requirements of the new situation. With China's imminent entry into the WTO, economic globalization was inevitable. To enhance the quality and grade of China’s lock products and reduce the gap with developed countries worldwide, it became necessary to revise the old standards. The State Bureau of Light Industry and the National Center for Daily Hardware Standardization issued notices to revise the original four door lock standards. The old pin tumbler lock (SG205-80) and external double latch lock (GB8385-87) were merged, and the addition of the double-latch (tiger) lock formed the new standard for external door locks. The current light industrial standard QB is the revised new standard.

The revision principle was to only improve upon the existing standards, never to lower them. Efforts were made to fundamentally change the backward situation of low product grades, low prices, and poor technical levels. A serious research approach was taken, with differentiated handling based on specific circumstances. During the revision process, foreign advanced standards such as the American ANSI, British BS, and Japanese JIS were partially adopted. In accordance with national laws and regulations and based on practical product conditions, different grading requirements were established during the revision process. External door locks and ball locks were divided into Class A and Class B, clearly distinguishing between high-end villas/apartments and ordinary residential units.

The new standards are higher than the original ones. The main indicators of Class A external door locks reach the level of British BS5872 Grade B, while Class B exceeds the original standards but falls below the British BS5872 Grade B. The main indicators of Class A ball locks are close to the second-grade locks of American ANSI/BAMA.A156.2-1996, and the Class B indicators are close to the third-grade locks of the same standard. Thus, the newly revised door lock standards QB/T2473-2000, QB/T2475-2000, QB/T2474-2000, and QB/T2476-2000 are all higher than the original standards.

Lock Knowledge Column Four

Considerations Before Purchase

Before purchasing a lock, consumers should consider the following aspects:

1. The location and importance of use.

Consider whether it will be used on front doors, hallways, rooms, bathrooms, or corridors to choose the appropriate functional product.

2. Environmental conditions and specific requirements.

Consider the environment's conditions, such as dryness/moisture levels, door structure, thickness, left or right-handed opening, inward or outward opening, to avoid purchasing the wrong product.

3. Coordination with decoration.

Select products that match your personal preferences and ensure they coordinate with the decor.

4. Family member considerations.

Consider whether there are elderly, children, or disabled individuals in the household to choose products that are easy to use.

5. Economic affordability.

Based on family financial status, those with more resources can opt for high-end products, while others may choose lower-cost options. Regardless of the choice, ensure the manufacturer is reputable and offers stable quality. It is advisable to select products from well-known brands to avoid financial loss and unnecessary troubles.

6. Dealer reputation and service quality.

Avoid dealers who might recommend counterfeit or substandard goods for their own benefit.

How to Choose When Purchasing

When buying lock products, pay attention to the following:

1. Choose products from enterprises with high brand recognition, stable quality, and good after-sales service.

2. First check if the product packaging has complete identifiers (including product standards, grade, manufacturer name, address, production date). Ensure the packaging is secure, and verify that the instructions match the product, avoiding exaggerated claims.

3. Inspect the product's appearance quality, including whether all components such as the lock head, lock body, lock tongue, handle, and cover plate are complete. Check the color of electroplated or painted surfaces for brightness and uniformity, looking for signs of rust, oxidation, or damage.

4. Test the product's functionality to ensure reliability and flexibility. Compare at least two products. When purchasing a double-sided lock, test all keys on both inner and outer lock heads. Also, check the insurance mechanism, testing each lock at least three times.

5. Finally, inspect the key's teeth pattern. For example, for a five-tooth key, each type should have at least three different tooth patterns, avoiding the deepest teeth for the first and last ones to facilitate insertion and prevent breakage.