"fura-2" wrote in message
oups.com...
Greetings all: I'd like to generate a bunch of 3 to 4" disks of sheet
metal (pretty thin, 20-ish and thinner gauge), and am looking at
punches to do the job. Would a Greenlee-type punch preserve the
structure of the punch-out (I realize its main purpose is to make the
hole, but I'm actually interested in what will be punched out)? Is
there some other method that I'm not thinking of (I figure a hole saw
is too aggressive and will leave a pretty rough product on both the
hole edge and what falls out). Any advice would be appreciated.

Unless you use an external press there will be a hole in the middle from the
draw stud. The punch is also angled which tends to bend the piece that comes
out. I guess you could flatten a twenty gauge disk fairly easily. You would
want the old style punches, not the slug busters. What are you going to do
with the discs?