While not far from the truth, in aluminum, you can drill a pilot hole on your desired center and use a corner nipper and a file to make your square shape with a bit of work. I find cage nuts to be much easier to align screw holes with because of their ability to wiggle.
Chassis Maker Recommendations
Moderators: pompeiisneaks, Colossal
Re: Chassis Maker Recommendations
Just plug it in, man.