304 stainless steel expansion screws are commonly referred to as metal expansion screws. The expansion screw is fixed by the wedge inclination to promote the expansion of the frictional clamping force, thereby achieving a fixing effect. The screw has a thread on one end and a taper on one end. The outer bread is a piece of iron (some are steel pipes), the iron tube (steel pipe) has several cuts cut into two halves, stuff them into the holes of the wall, then lock the nut, pull the nut outward, taper into Iron cylinder. The iron cylinder is open, so it is firmly fixed to the wall and is usually used to fix fences, awnings, air conditioners, etc. on cement, bricks, etc. Widely used in environmental protection equipment, medical equipment, communication equipment, power facilities, electronic products, instrumentation, food machinery, petrochemical, ship assembly, pump and valve pipes, building curtain walls, etc.