Hard Metal Closed Hook Fasteners M8Golden 8MM-Pack of 4Pcs

The expansion screw is by using the wedge angle to prompt expansion and creates friction, to reach the fixed effect Need to use about 8mm diameter drill bit for drilling holes

The drilling depth should great than or equal to 10cm Installation: First, insert the expansion screw into the soil-cement admixture, hard twist the closed hook until can’t twist it anymore Second, screw the nut with wrench until it fixed Finally, tightening the closed hook