a 5/8 annular cutter has at least 4 cutting edges and maybe 5 compared to 2 on a drill bit. factor in that an annular cutter removes far less material than a drill bit and i don't think it is a stretch to say that it would last 2- 3 times longer with proper care, lubrication and or coolant, probably even longer.
when sharpening is required special equipment is needed for the annular vs. a drill bit can that be sharpened by hand or equipment that is much more common.
Not only that but if you are using a mag drill you have no (or extremely little) run out or play/wobble etc. And then a cutter will follow its cut once started. .
This alone makes twist drills/cutters last so much longer.
And cutters have a very small outside rib, = less friction=cooler temps.
A place in Illinois? sharpens cutters for like $7 or close to that. I have the link saved somewhere. Totally worth it, but I have yet to send any out.
I think I read the sharpening machine is either $3,500 or $5,500 ??? It was a lot, I remember that.
