What is a self-tapping screw

Self-tapping screws generally refer to the pointed, coarse teeth, the texture of the harder wood screws, but also used in aluminum alloy, plastic. A special self-tapping screw used for metal hole opening threads is called a silk attack. Self-tapping screws for non-metallic or softer metal, do not have to hit low holes and tapping; self-tapping screws self-tapping screws are pointed, so talent  "self-attack "; The general screws are flat head, The thickness is common. Self-tapping screws are said: Drill hole for no need to attack the hole, with the screws and the general is not the same, the head is pointed, the tooth distance is relatively large, and the chip-free wire attack is a bit like, can not have to attack the teeth directly spin into, metal and plastic generally use this method. It can be consolidated on the data, by its own thread, will be fixed knot "attack-drill, squeeze, press" out of the corresponding thread, so that it works closely with each other. Self-tapping screws are mostly used for the connection between thin metal plates (steel plates, saw plates, etc.). When connecting, the threaded bottom hole is made for the connecting piece, and then the self-tapping screw is screwed into the threaded bottom hole of the connecting piece. Because the thread appearance of the self-tapping screw has a high hardness (≥HRC45), the inner thread can be captured in the threaded bottom hole of the connecting piece, and then the connection is formed.