The fixing principle of the expansion self tapping scre […]
The fixing principle of the expansion self tapping screws is that the expansion screw is fixed by the squatting shape to promote the expansion to produce the frictional gripping force, and the fixing effect is achieved. The screw has a thread at one end and a vertebra at the end. The outer bread has a tin and the iron cylinder has a few incisions in half.
Put them together into the hole in the wall, and then lock the nut. The mother pulls the screw out and pulls the vertebra into the tin cylinder. The iron cylinder is Opened up, so it is fixed on the wall, generally used for the fastening of fences, awnings, air conditioners, etc. However, its fixing is not very reliable. If the load has a large vibration, looseness may occur, so it is not recommended to install a ceiling fan.
Expanded self-tapping screws now have stainless steel expansion tapping screws and plastic expansion self-tapping screws, the specific use is not the same.
After tightening, it will expand. There is a big head at the end of the bolt. The outer sleeve of the bolt is a round tube slightly larger than the diameter of the bolt. There are several openings in the tail part. When the bolt is tightened, the tail of the big head is brought into the open tube. The tube is flushed to achieve the purpose of expansion, and then the bolt is fixed on the ground or the wall to achieve rooting.