On Sun, 15 Jan 2006 23:21:49 -0500, "billh"
wrote:

you can then drive a sacrificial one in
little by little and make square corners.

This is HSS and I have tons of it (literally a few bucketfuls,
collected from ton quantites handled as scrap over the years). I was
thinking about being a bit more careful with a grinder, putting a few
sharp edges onto it and making a real broach tool out of it. Only
problem with that is that you really need two-sided access for
broaching, so I'd have to make a tube and then weld it onto the handle -
this might then distort to be less accurate than a more crudely cut
hole.

I'm not that keen on the grubscrew because I'm really a metalworker. I
can probably make more handles and braze inserts into them faster than I
can drill and tap good sockets.