Ian Stirling wrote:
Jerry Built wrote:
Once [the drill bit has ] got too hot it's useless without
re-hardening/sharpening, both of which it is *possible* to
do at home.

I'd disagree. For HSS bits, it's practically impossible for
most people to do retempering at home.

I thought I'd replied, but it seems not, so here again:

I said possible,not that most people can do it without
knowing how. What's the difficulty with hardening, then
warming the shank until the tip is right, and quenching?
What's the difficulty, I'm puzzled (unless you're talking
about small drills) ?
--


J.B.