DoN. Nichols wrote:
..."Dub" means to grind a flat on the edge of the end flute
parallel to the axis of the bit so it does not dig in. ...

"parallel" to the axis? IOW, the outer/circumferential edge? I thought
it was the cutting edge that was "flattened". I.e., lessening the
relief angle. Not that I've ever done this.

But I like to learn,
Bob