Guess you all missed my post.If it's a 12" saw it will most likely have a 1" arbor. I don't think many 12" saws were designed to run on 115 volts at 10 AMPs, just not enough HP for that size blade. Having said that, my 12" Craftsman radial arm saws did have a 5/8" arbor, but were wired for 240 VOLTs. They were "homeowner" saws, not commercial/industrial grade in spite of the hype in the catalog...