Yesterday I was trying to drill holes in our daughter's garage floor to anchor our SIL's gun safe. Now I have drilled cement to install floor anchors for over thirty years during my work at the phone company. That is how we anchored the equipment in place. It was never a problem with masonry drills, but not that garage floor. I have never encountered cement that hard. We were using new carbide bits and we could hardly make a little dust. I used a quarter inch pilot drill and it wouldn't go either. I should point out that I have drilled garage floors before with no trouble. My lathe was held in place with floor anchors. Are they making harder cement these days. Any ideas?