In article ,
"Mike Marlow" wrote:

Wow - that seems like a restriction that makes those wheels almost
impractical for most use.

True, their main use is for sharpening High Speed Steel, and powdered
metal turning tools. They cut faster and cooler, than stone wheels. And
since they never need truing, you can mark the wolverine, or other jigs
for different tools and be able to reset to those markings for repeated
sharpening. When you true stone wheels a couple of times, it decreases
the diameter of the wheel forcing you to change the setting of your jig,
so that you don't change the grind angle on your tools.