Richard J Kinch wrote:

tomcas writes:


Like Dan G said- use your drill as though it were a reamer. Just
predrill first with a drill that's .005 to .010 undersize and then
follow up with your final drill size.


Hmm, you tried that? Or is this just what you imagine? In my experience,
drills cannot ream. You can't use such a small step up in drill size, it
won't cut, it just rubs and smears the metal. That's why there has to be
reamers for reaming.


I hope I'm not imagining it, I've done this a couple of hundred times in
the past 26 years. Depending on the hardness of the metal and sharpness
of the drill any material removal over approximately .002 cuts and does
not abrade. Sure reamers do a better job and when the desired size
reamer is available I naturally go that route but in pinch I've found
this method works fine.