On Sun, 28 Apr 2013 21:53:48 -0500, Richard
wrote:

On 4/29/2013 5:50 AM, Lloyd E. Sponenburgh wrote:
fired this volley in
m:

Probably would hurt to have several bits handy...
You probably gonna break a couple on this job.

This is not a job for a hand drill.

It's not so much the problem of holding the bit straight, but rather one
of regulating the pressure and cut per tooth... which is difficult to do
by hand with that small a bit and that material (although he didn't say
_what_ stainless..)

Even one of those $29.95 "drill press stands" improves your likelihood of
success, where the speed of feed must be controlled carefully.

As said before -- never let off on the pressure, except by rapidly
retracting the bit. Never allow it to 'idle' on the bottom of the cut,
or you'll work-harden the steel. Prick-punching will also work-harden
it. That might not be a problem with a 1/4" bit, but with a 1/16" drill,
you be hardening almost the entire cutting footprint of the drill.

LLoyd


I've done this kind of drilling before and nearly always break a bit -
when breaking through the bottom side.

What did I do wrong?

You didn't "lighten up" :-)

As the drill point breaks through the bottom of the work the area of
the drill point that is opposed by metal decreases, thus the pressure
(in PSI) increases unless you reduce pressure on the drill press
handle...

--
Cheers,

John B.