Hole punches

[Phil@sievers.com (Phil Payne)]

In message <16422BE442B@agcom.tamu.edu> "Al Powell" writes:

[snip]

> I remember that in the Ag Engineering machine shop, they had some two-
> piece dies to make holes through sheet metal.  You drilled a small 
> hole for a bolt connecting the two pieces, which were round cup-
> spaned dies.  The smaller fit inside the cavity of the other, and had 
> cutting edges.  The basic technique was to drill a small hole 
> through the metal for the bolt, connect the dies with the bolt, then 
> tighten the bolt, and the smaller die but thru the sheet metal while 
> being braced against the larger die on the opposite side of the 
> metal.  No warping, no slipping.
> 
> ASCII art attempt:           __________
>                              |        |   Large die
>                              |        |   
>                               |______|     Small die
> 
> 
> Anyone know what those dies are called?

I call mine a hole punch.  They were indispensible in amateur radio shops back 
in valve (tube) days, for punching holes in radio chassis.  "The place to go" 
to buy a set ten to fifteen years ago would have been an amateur radio 
supplier. Perhaps a friendly ham near you still has a set?