On Tue, 10 Nov 2009 11:56:37 -0600, Tim Wescott wrote:

On Tue, 10 Nov 2009 13:06:53 +0000, Chris Wilson wrote:

I seem to remember being taught in school that metric countersunk Allen
srews had a 90 degree countersink angle, and Unified had an 82 degree
angle. Is that right, and does it matter if I just use a 90 degree
countersinking bit for both, as here in the UK no one seems to stock 82
degree bits for ferrous material? Thanks.

You can't resharpen the drill bit to any angle you want?

Isn't that what bench grinders, hands, eyes and brains are for?

I don't have the necessary skill for that, but thank you for the
suggestion. I do pride myself on polite and generally sarcasm free replies
to strangers though