it's odd they sell the 9 inch angle grinder, but not the 9 inch cut-off wheels for it.. you'd have to use the 7 inch cut-off wheels, which only have the 5/8 hole, instead of the 7/8 hole.. and when the hole gets punched out, hopefully, you can remove the material, and safely use the 7 inch cut-off wheel.. in the punch out process, the wheel gets distorted, which is unsafe at best.. but that's what they sell that's closest to what would work.. they don't even sell the proper 9 inch cut-off wheel!.. just grinding wheels for it!.. odd company!..