The product information does not indicate that the shank is 1/2". Most lightweight Drill bits have 3/8" plugs. Mine too. When the hole saw arrived I couldn't use it and wanted to return it and just buy a hole saw at a local hardware store. Unfortunately I got a 1-3 hole saw /8", I had to buy a set for $84. Rather than buying something I didn't need, I decided to buy a 1/2" hole punch for $99. (Well, I didn't need that either, but a new one is a lot more fun than a dozen crowns.) So I used this hole saw. It worked great on 3/4" thick plywood. Now I can finish installing the bathroom fixtures.