Here is a punch I made on a CNC mill for punching 0.032 aluminum. It is a test case for a bigger punch and has some of the shapes/curves of the full size one. Did the modeling/CAM in Fusion 360. Plates are 3.5" x 4" x 0.5 thick steel - no hardening since the number of hits is low. Clearance is 0.004". Dowel pins for alignment and also for a 1/8" hole. Edges are very smooth with no burr - better than I expected.
Attachment 383628
Attachment 383626