─ It can be easily screwed into the drywall during assembly. A hole is drilled in the steel bar and a matching female thread is tapped. The recessed bearing face of the horn can be used to prevent damage to the wallpaper or plaster surface during screwing. Most of the self-tapping screws are for commercial use. For example, when the self-tapping screws are provided with a combination screw (SEMS), they can provide a more compact service. The screws, such as a special designer with thick and thin threads, focus on the anti-looseness after assembly. .
Thread forming ─ ─ directly developed from the iron screw, thread forming tapping screws must be drilled in advance, and then screw the screw into the hole, strong extrusion with the female thread, and the original material in the female thread position will be Extruded between the male threads, this is referred to as a thread forming tapping screw. It is only applicable to thin and plastic materials and has therefore been developed; thread cutting self tapping screws ─ cut one or more lines at the end of the thread The cutting port, when screwed into the pre-drilled hole, enables the use of screw-tails and teeth to cut the mating thread in a manner similar to tapping. It can be used in thick plates, which are relatively hard or brittle materials that are difficult to shape.
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 self-tapping screw thread and the bottom of the teeth, because the friction force is smaller than the thread forming self-tapping screw. It can therefore be used on 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 a self-tapping screw a true “structural” fastener.