hduiweh duieyfe's Album: China Self-tapping screws Suppliers

Self-tapping screws combine taps and bolts. The front is a tap and the back is a thread. In general softer materials, you can directly screw it in by drilling an empty space. The thread is tapped by the tap, and then the bolt thread is fastened. If the screw diameter is small, the material is also very soft. It is even possible not to punch first, such as screwing it into wood. Find more at:http://blog.xuite.net/shapedbolt/bolt/581082099