Stainless steel expansion bolt is fixed by using the sway inclination to promote expansion to produce friction wrapping force and achieve the fixed effect. One end of the screw is threaded, the other end is vertebrous, and the outside is covered with a sheet of iron. Half of the sheet cylinder has a number of incisions. Thicken them together into the hole punched in the wall, and then lock the nut. The nut pulls the screw outward, pulls the vertebrosity into the sheet cylinder, and the sheet cylinder is lifted, so it is tightly fixed to the wall, generally used for protective railings and bars. Fastening of awning and air conditioning on cement, brick and other materials.