10-Piece Hole Saw Kit for Wood | Durable Carbon Steel Power Drill Hole Cutter with High Precision Cutting Teeth – Woodworking HCS Hole Saw Kit for Wood, PVC, Plastic, Drywall

Bought these since the set I had was missing a size or two. Used it to cut into some very dense plywood using my drill. It got hot enough to smoke so I had to stop and let it cool a few seconds and use a wire brush to remove the wood that got stuck on the teeth, but after a couple of bites it made it through each time. No warping or damage to teeth after drilling about a dozen holes. I also liked this one because it came with one drill bit for all the hole saws, unlike another set I returned where some of the hole saws only fit the larger drill bit which was too big for my 3/8 drill.

There are no directions for first time users. They are not very sharp so took quite a while to get through the wood. Leaves the wood very chipped around the hole. I am not experienced enough to know if thats normal. It came quickly from the seller.