Product : Size : thread diameter : 8 mm, unit length : 60 mm, the supreme load-carrying capability : 170 kg. : 304 unsullied steel. : 201g Expansion is created by tightening a rib bolt which draws a pointed cone expanding a sleeve against the walls of the hole. How to use : the expansion screw into the ground or the hole on the wall and then tighten the nuts of the expansion bolt with wrench. The bolt outdoorsy while the metal sheath does not move. Thus the bigger head of the bolt will the metal sheath, making it fill the full hole. Now, the expansion screw can not be out. Widely in fence, protected doors and window, canopy, air conditioning rach fixation, home decoration, engineering, etc.. No, no deformation,non-pollution. Package : 5 * expansion bolts .