Review on Efficient Expansion Internal Fastener: Stainless Lifting Simplified by David Dortch

I used a Dewalt DW5234 7/16" carbide hammer drill bit and drilled three inches into the concrete wall and then tapped it with a hammer to ensure a secure fit. If you use a larger drill bit ,something you have to glue the fastener into the concrete before tightening the screw as it just rotates in the hole great product no complaints!