[sanddrag]

We have a standard 1/2" McMaster push broach which we use in our ~3 ton arbor press in a pinch, when we need to do something in-house. It works well enough, but this is about as small of a press as I'd go for this. The pinion in the press has since let a couple teeth go.

A pull broach would be the best in terms of perpendicularity and whatnot, but these are usually found only in specialty broaching shops.

You can also broach in a very large lathe or horizontal milling machine, if you have access to one of those. And when I say very large, I mean >2000lbs. I would fear it could damage a smaller machine. A press is the definite way to go if using a broaching shop is out of the question. I think a larger arbor press would be preferable over a hydraulic press in this application, for the better feel for things. On an arbor press you'll know when something is wrong.

Just be careful to never drop the broach! Best to have a box with a pillow or something under the press. Don't trust yourself to hang onto it / catch it.

Also, remember to use lots of oil!