Can the spring seat cutters with arbor be operated with a hand held drill. or do they need to be set up in a mill? Thanks, Joel

https://www.compcams.com/cutter-for-spring-seats-cuts-to-1-680-od-560-id.html

I found it on youtube. A drill is ok.

Be very careful on cutting the seats, I have hit water on stock 340 heads at .030 cut down
I don't cut them down any more except the inner step to get it level with the main spring seat for dual springs
I use a old Craftsman 5/8 drill motor that turns real slow

For many years I dropped a .030 valve spring shim meant for stock spring seats on before I cut for larger diameter springs. When the cutter got down to the shim, the shim would spin and keep the cutter from digging farther down. That was mostly to keep me from hitting water. I normally used a drill press. When assembling the new springs, a standard .030 small diameter shim went down on the bottom to make for a flat surface.

Thanks for the replies. I'm not going to increase the depth, I just need to increase the diameter a little bit.