Flat-head self-tapping screws - can be easily screwed into the drywall during assembly, drill a hole in the steel bar and tap out the female thread. The recessed bearing surface of the horn of the horn can not be destroyed during screwing. Wallpaper or plaster surface. Most flat-head tapping screws are for commercial use. For example, when self-tapping screws are provided with a combination screw (SEMS), they can provide more compact service. Screws, such as special designers with thick threads, are Focus on the anti-loose after assembly.
Flat-head self-tapping screw thread forming ─ directly developed from the metal screw, thread forming tapping screw must be drilled before use, then screw the screw into the hole, strong extrusion with the female thread, and the original position in the female thread The upper material will be squeezed between the male threads. This is referred to as a thread forming tapping screw. It is only applicable to thin, malleable materials and has therefore evolved; thread cutting tapping screws ─ cut at the end of the thread One or more cutting ports enable the use of screw-tails and teeth in a similar manner to tapping the female thread as it is screwed into the pre-drilled hole. It can be used on thick plates, which are hard or brittle, etc. Shape the material.
6 Thread rolling - Taper tapping screws, also known as Type TT (Type Tai is still patented) is based on the principle of forming screw tapping, thread rolling into tapping screws with specially designed thread and tail end The screw can be rolled into the matching female thread under the intermittent pressure. At the same time, the material around the hole can more easily fill the space of the tapping screw thread and the bottom of the teeth, because the friction force is smaller than the thread forming self-tapping screw. Therefore it can be used in thicker materials, the torque required for rotation is better controlled, and the combined strength is higher. The thread is rolled into self-tapping screws and its engineering standard definition is better than forming or cutting tapping screws in materials, heat treatment, strength The definition is higher and clearer, making the thread rolling into self-tapping screws become a true “structural” fastener.