Self tapping screw is simply a screw that can tap itself. The difference between self-tapping screws and ordinary screws is that ordinary screws must have a processed screw hole to screw in. Self tapping screws do not need to screw in at the same time their own tapping. In order to achieve their own tapping purposes, the hexagonal drill tail screws are generally pointed, in order to facilitate squeezing into the object to be screwed into.

Self-tapping screws are usually described by screw diameter series, screw number per inch length and screw length. There are 10 and 12 screw diameter series, the corresponding screw diameter is 4.87mm and 5.43mm respectively; There are 14, 16 and 24 threads per inch. The more threads per inch, the better the self-drilling capability.