I think I would chain-drill around your hole and then clean up with the
Armstrong milling machine (a round file). Buy a new top quality file with
a handle - splurge, it will be maybe $5. I used a brand new round file the
other day for the first time in my life (hey, I've acquired a *lot* of used
files in my day) and oh man did it cut!

Grant Erwin

Dave in MD wrote:

I'd like to drill a 1 5/16" (1.3125 inch) hole in a 1 inch thick mild steel
bar. I only have a drill press in my shop. Is there a way to drill a hole
this big in a home shop, without a milling machine?

It has been suggested I try a HSS hole saw at low RPM (less than 400) with
plenty of cutting fluid.

It doesn't have to be pretty, and the jig I'm making doesn't require super
high precision.

Thanks,
Dave