Bought this hole saw because it was the right price and with a carbide tip this thing can cut through anything - I made a mistake cutting 0 .25 sheet steel with no clamps, it got stuck and, oh, butt pinched and then went off again, my 9 amp drill decided to move my wrist in an unnatural and painful way. Stick until I had a groove, it worked until I got to the end and hit a ridge on the back so I turned the stick over and voila I had a hole, the saw was fine, still sharp like new , but it fits better on a drill - if my drill didn't have a brake I'd wear a cast - would recommend to anyone who has a drill.