Easy to install. Standard size. Used in concrete and masonry. Expansion is created by tightening a threaded bolt that draws a tapered expansion cone of a sleeve against the walls of the hole. Stainless steel finish provides protection against rust. Product Details: Size: thread diameter: 6mm, length without ring: 70mm. Material: 304 stainless steel. Weight: 210g Working Principle: Place the expansion screw in the ground or the hole in the wall, and then tighten the nuts of the expansion bolt with a wrench. The bolt comes out while the metal sheath does not move. So the larger head of the bolt will expand the metal sheath, causing it to fill the entire hole. Now the expansion screw cannot be removed. Widely used in fencing, burglar-proof doors and windows, canopy, air conditioning fixing, home decoration, techniques, etc. Expansion is created by tightening a threaded bolt that draws a tapered cone that expands a sleeve against the walls of the hole. Notice: If the load is subjected to strong impact, it may come off. So do not recommend installing a ceiling fan, etc. Package including: 5 * expansion bolts