Screws can be used in airplanes, ships, and industries. How can we judge the quality of screws? How can we buy good products?
1, from the screw manufacturers to see how many years, good manufacturers, manufacturers of screws for a long time production of products (Product) better than the time is shorter; staff are also better than the average general staff;
2, a good screw, the color surface color is uniform, and the supply of each batch of product color (Product) consistent, its overall standards can meet the national standard requirements;
3, if the head of the screw eccentric, boring head, head is not round or full, flash and other phenomena, do not buy its product (Product). Electrical screws are "quantity products" and are not hand-made artworks. In mass production, they are aimed at achieving high-precision, stable quality and consumer prices.
Although the screws are small, they are of great use. Screws are used in transportation equipment, airplanes, trams, and automobiles. Electrical screw precision is usually 6g (2nd grade, U.S. specification "IFI" is 2A teeth), crude screw used in construction projects is 8g (3rd grade, "IFI" is 1A teeth). The value of screws is very important. There are examples in the world of bankruptcies caused by poor screw quality. There are also examples of aircraft falling down and vehicles being subverted due to poor screws. Stainless steel screws usually refer to steels that are resistant to the corrosive effects of air, water, acids, alkali salts, or other media. According to the different composition of the alloy, the stainless steel and the acid resistance are respectively emphasized. Although some steels are stainless, they are not necessarily resistant to acids. Acid-resistant steels are usually stainless steel