First look at the lock implementation standards Foreign countries have very strict standards for hardware locks, so the quality of imported products is relatively high. We can feel the quality of the locks. Generally speaking, the heavy lock has a relatively high quality; the lock body can not be pointed, and the tip is easy to injure, especially the lock handle end, the lock tongue and the lock body are three positions; the lock spring is good. Flexible opening, high sensitivity and long service life. There are also many styles of locks, so be sure to keep in mind the style of the interior doors. Second, look at the lock material The lock material on the market is basically divided into stainless steel, copper and zinc alloy. High-strength stainless steel, strong corrosion resistance, no discoloration, is the best lock material; copper is more versatile, mechanical properties are superior, and the price is higher; the lock high-quality zinc alloy is strong and wear-resistant, corrosion-resistant, and easy to form. Mostly used for mid-range locks. Look at the lock surface treatment home improvement supervision again) The surface treatment is roughly divided into electroplating, spraying and coloring. The locks form a dense protective film on the surface of the product through surface treatment, which acts as anti-corrosion and anti-rust, making the lock more beautiful and durable. The dense protective film is also a standard for measuring the quality of locks. The locks of good quality are mostly plated, the coating is fine and smooth, even and moderate, the color is bright, and there are no signs of bubbles, rust and oxidation. Editor in charge: Zhao Hongli As a functional raw material for whitening cosmetics, whitening agents have received great attention. Its development and application research has been deepened, and new high-efficiency and easy-to-match raw materials have been introduced in the market. Countries have invested a lot of manpower and material resources in the mechanism of skin whitening agents, the development of new whitening agents and the application of whitening agents, and have made significant progress. Many new whitening agents have been applied to products. Whitening Agent Jinan Huijinchuan Chemical Industry Co., Ltd. , https://www.hjcchemical.com