Fred, et al, in the future, if you have to sculpt concrete, use a rotary hammer, not a hammer drill. What's the difference? Glad you asked.

My mechanic recently moved into a new building, and had to re-install his lift. He used about six hours and two 3/4" carbide bits in his DeWalt hammer-drill drilling two of the 6"-deep holes for the anchors. (Each post needed 6 holes)

When I showed up and saw his frustration, I broke out my Bosch SDS-Max rotary hammer. It took me less than 5 minutes to drill the remaining holes, no exagerating. In the hammer-only mode, I can drive a ground rod in less than one minute, whereas it takes up to a half-hour with a sledge hammer.

There's nothing like having the right tool for the job, even if you have to rent it.

Larry
www.fineelectricco.com