On 7 Sep 2005 16:48:52 -0700, the renowned "fura-2"
wrote:

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.

Greenlee punches require a drilled hole (maybe something like 1/2" for
that size, I don't recall) and they cut with a curved edge, so the
result is a rather curved slug with a fairly large hole in the middle,
probably not what you want.

If a hole in the middle is acceptable, maybe you could stack blanks
and turn them on a lathe.


Best regards,
Spehro Pefhany
--
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