The use principle of expansion bolt is very simple, that is to make the diameter of the fixed screw bigger with the help of it. It can completely exert pressure on the wall other objects, thus increasing their abrasion force. Greatly increased the screw tension, to ensure the stability of the object to be fixed. The use of expansion screw is to make the object more stable. The inclination of the screw the expansion screw produce greater wear difference force, so as to achieve more stable effect. One end of the screw is threaded the other side is tapered. The outer packing is just a sheet of iron. If there is a cut in the half of the sheet metal, then we'll stuff them together into the hole. After locking the nut, pull out the nut open the taper iron sheet so that it can be firmly fixed on the wall. Generally used is the protective fence, the canopy the air conditioner are fixed. But sometimes fixed is completely reliable, if the load is large, it will easily cause fall off, so generally do use in the family ceiling fan fixation.

The working principle of the expansion screw is to hit the expansion screw on the ground in the mouth of the wall. Screw the nut tightly with a wrench, the screw will naturally go out. However, the metal jacket will move, so there will be a metal sleeve opening under the spiral, so that the whole hole is full. At this time, with the help of expansion screws, the work is much easier. At present, the expansion screw has been widely used in the construction site. With its help, the current fixed work becomes more secure. Compared with before, it has a good effect is widely recognized by people.