On Mon, 10 Sep 2007 15:51:56 -0400, "Tom Nie"
wrote:

William,
Did some Google homework. Still, I seem to have only found machine broaching
and it seemed from your answer that this was something we could do in a home
shop. Do you use a hammer/chiseling action or even a rotary hammer like SDS
bit?
Can't seem to find explanations for someone who's ignorant of the process
entirely

Think of a hack saw or reciprocating saw blade. It's similar to that,
only wider. You push it in, and it cuts and pulls out the shavings as
you pull it out. I suspect hammering and chiseling would be very bad
for the tool- most of the broaching I've seen is done at a fairly slow
speed. The tool is very hard, and as metal gets harder, it tends to
become more brittle and can't take impacts very well. The arbor press
is a pretty good idea, but it's still probably more than you really
need if you're just making one or two of these.

If you're willing to invest some extra time and elbow-grease, you
could always file the corners out as well, though I can't think of too
many people with the time or patience for that.