The expansion screw uses the wedge-shaped inclination to promote the expansion to produce a frictional grip force to achieve a fixed effect. The working principle is as follows: the expansion screw is composed of a screw and an expansion tube, and the tail of the screw is conical, and the inner diameter of the cone is larger than the inner diameter of the expansion tube. When the nut is tightened, the screw moves outward, and the conical portion is moved by the axial movement of the thread, thereby forming a large positive pressure on the outer circumferential surface of the expansion tube, and the angle of the cone is small, thereby making the wall and the expansion tube Friction self-locking is formed between the cones and the fixing effect is achieved.
In fact, the installation method of plastic expansion screws is very simple, and the tools required are electric drills, or drills, hammers, screwdrivers, and the like. Use a drill bit that is the same size as the outer diameter of the plastic expansion screw.
The depth of the hole is 2 mm deeper than the total length of the plastic expansion screw. After the hole is punched, the plastic expansion screw sleeve is punched in. Then tighten the screws with a screwdriver and lock the items to be installed. Hammering is hammering in, the rest are screwed in.
