Expansion screws

　　Generally speaking, expansion screws are metal expansion screws. The fixation of expansion screws is to use the wedge slope to promote the expansion and produce friction grip force to achieve the fixing effect. One end of the screw is threaded and the other end is tapered. There is an iron sheet (some steel pipes) on the outside. There are several cuts in the half of the iron sheet cylinder (steel pipe). Insert them into the hole made on the wall together, and then lock the nut. The nut pulls the screw outward to pull the taper into the iron sheet cylinder. The iron sheet cylinder is expanded and tightly fixed on the wall. It is generally used for fastening the protective fence, awning, air conditioner and other materials on cement, brick and so on. However, its fixation is not very reliable. If the load has large vibration, it may loose. Therefore, it is not recommended to install ceiling fan, etc

product profile

The expansion screw is composed of screw, expansion pipe and other components. The tail of the screw is conical, and the inner diameter of the cone is larger than that of the expansion pipe. When the nut is tightened, the screw moves outward, and the conical part moves through the axial movement of the thread, so as to form a large positive pressure on the peripheral surface of the expansion pipe. In addition, the angle of the cone is very small, so as to form friction self-locking between the wall, the expansion pipe and the cone, so as to achieve the role of fixation.
The spring washer on the expansion screw is a standard part. Because its opening is staggered and elastic, it is called spring washer. The function of spring washer is to use the sharp angle of the wrong mouth to pierce into the nut and flat washer to prevent the nut from loosening.

The flat pad is also a standard part. Its function is to evenly distribute the pressure of the nut on the connected parts.