This kind of part is the domain of a turret punch machine. Even the countersinks can be done (a special countersink tool and its corresponding prepunch round tool for a turret costs around $450).
It looks like you are generally focused on building these yourself (I'm the same way), but it really is such a simple and quick job for a shop with a turret - so you really might want to look at sending this job out.
1500 pieces isn't a large enough quantity to justify the expense and headache of building a dedicated die to punch it out in one shot. My guess is that a shop with a turret will be able to bring it in at below your cost (either if you were to continue to mill them out, or if you tried to build that die). |