I used this to cut 4 inch round ceiling boxes in a 96 year old house. Ceilings in horsehair stucco and slats. Pipe wiring that runs directly through the plaster. I use this hole saw with a suitable mandrel in a large 1/2" variable speed cord bit. Running slowly, returning frequently to clean up and cool is great. I was able to cut through both plaster and batten. The hole was very clean and the hole saw is still in shape like new to cut a lot more.