Magical use of stainless steel screws

There are many types of screws, whether it is a miniature screw for glasses or a large screw for large-scale heavy electrical engineering. The main purpose is to make high-level industrial products form a fixed one. If the screw is tightened too hard, the screw head will break off, or if the tooth pattern is not properly locked, it will not meet the conditions of use, which are all problems of quality and accuracy. Screws are "mass products", not hand-made works of art. In mass production, the purpose is to achieve high-precision and stable quality and popular prices to supply consumers. The accuracy of screws is usually 6g, and the rough screws used in construction projects are 8g.
The main categories include ordinary screws, self-tapping screws and expansion screws.