On Tuesday, November 10, 2015 at 5:41:07 PM UTC-8, John Doe wrote:
I suppose that's a good use for a grinder, when a rotary tool cutoff wheel
won't make it deep enough through the material.

...for cutting through tool steel

Depending on the cut desired, EDM or ultrasonic (impact grinding)
solutions can handle most any hardness of material. If you
just want a slice, there are metal cutting abrasive blades for
table saws or Skilsaws (beware sparks, though).

And in a pinch, people have used copper disks and a slurry of
abrasive/glycerine/water to do the same sort of work. It's
not as fast, though.