I have a set of these I made from the piston on an old hyd. cylinder, but I never thought to pair it with the punch.

Can you punch and flare all at the same time? or 2 operations?

Hey, Tom- Is punching holes a weight reduction technique? I can see where the inward flare reduces the sharp edges, but for a newbie, what's the rationale for that?
I stiffens your large flat surfaces of sheet metal, much like rolling a bead. So you get the benefit of weight reduction and a stronger sheet metal part, all while moving the sharp edges away from you. Tom is right, looking like an octopus attacked is not a good thing...LOL

not to mention it looks cool!