:Application:Principle Expansion of the screw fixed principle: the expansion screw fixed but the use of pull-shaped gradient to promote expansion of the friction grip force, to a fixed effect. Screw is a thread, a vertebral end. Outside the package of a tin, iron cylinders have a number of incision, thaw into the wall with them thrown into the hole, and then lock the nut, nut pull the screw, the vertebral pull into the iron cylinder, iron cylinder was up Open, so tightly fixed to the wall, generally used for fences, awnings, air conditioning and other materials in the cement, brick and other fastening. But its fixed is not very reliable, if the load has a large vibration, may occur loose, it is not recommended for the installation of ceiling fans.
Expansion bolt is the principle of expansion bolts hit the ground or wall hole, the bolt with a wrench to tighten the expansion nut, bolts go out, while the outside of the metal sleeve does not move, so the bulk of the bolt under the put The metal sleeve opens up to fill the hole, and the expansion bolt does not come out.