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Old 11-01-2012, 10:00 AM   #1695
jdrocks OP
Gravel Runner
Joined: Jul 2007
Oddometer: 4,585
Originally Posted by nuggets View Post
Thanks for the hole cutting info. I'll have to grab some of those hole saws.

You use a hand drill for that? My drill press doesn't go below 600rpms (lil' 12 delta).
in the home shop environment, 600RPM is too fast for all but the smallest hole saws and small diameter high speed twist bits. speed means heat, and heat kills the tooling. unless you can safely add a variably speed switch to your drill press, you're better off using it for accurate pilot holes only, finishing the cut with a variable speed electric hand drill. same goes for larger diameter holes with conventional bits. use cutting oil, it's cheap, good quality tooling isn't.

almost all hole saws accept a 1/4" centering bit, commonly a 1/4" high speed twist bit. i never drill a hole with this bit, instead drilling a 1/4" pilot hole with a regular twist bit, then finishing the cut with the hole saw mated to a piece of 1/4" drill steel or a broken 1/4" bit ground flat on the end.

you can download a PDF of recommended cutting speeds for common bit diameters used for drilling the normal materials you encounter.

hole saws are notorious for binding in the work if you're not careful. observe safety precautions.

i use hole saws with both a variable speed drill press and a variable speed hand drill.
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