When using a cut-off wheel for a Dremel or similar tool, should I be running the Dremel at high speed (high RPMs) or low?

I don't know that the application matters, but I'm cutting a bunch of bolts. I want a decent job, but I'm not worried about aesthetics. I guess I'm mainly interested in the long-term health of the cut-off wheels (though, of course, long-term for an abrasive wheel is pretty short).

  • If you have a lot of these bolts to cut off,you might be better served with a full sized angle grinder with a cutoff disk. Even a cheap angle grinder should out perform the dremel and the cutoff disk is much less fragile than the dremel disks.
    – Johnny
    Commented Dec 30, 2013 at 18:07

2 Answers 2


Straight from the horses mouth:

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Step one - personal protective gear!

High speed, low pressure, and try to avoid sideways (flat way on the disk) movement or twisting in the cut. If the motor bogs down, reduce pressure. Edit: unless your abrasive wheels actually mention a top speed, and it's lower than the fastest your machine goes.

Expect to break some - aside from the hot sparks, fragments of cutoff wheels are the major reason for safety glasses and gloves - it's tricky to keep things perfectly aligned for correct cutting all the time, and when I screw up they break - I assume that applies to other folks as well, but feel free to call me a klutz if you only wear them down, rather than breaking any ;-)

  • cannot stress the safety glasses enough whenever using a Dremel. Especially the cut off wheels. I've had the regular ones shatter many times. The 'Reinforced' and and the EZ Lock cut off wheels haven't had the same issues but still wouldn't chance it without safety glasses. Commented Dec 30, 2013 at 17:38
  • +1 for fiberglass reinforced, they last much much longer.
    – Ethereal
    Commented Dec 31, 2013 at 16:06
  • The fiberglass wheels are more robust - but they are also thicker (meaning both a bigger slot and having to cut more material since the slot is bigger.) Depending what you are doing, both types have their place.
    – Ecnerwal
    Commented Dec 31, 2013 at 18:07

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