These tables assume mild steel at 50kpsi. Add perhaps 30% for stainless.

A couple more things from your other posts: you will get edge effects
where the metal pulls in if you try to punch within about 1x to 2x metal
thickness of the edge. Your 1/8" from the edge on 1/16th material is
fine. Thicker will give you trouble.

Also: punching is pretty much limited to cases where the diameter is
greater than the thickness of the material. Get even close to that point
and the the edges are terrible as well as lousy punch life.

The way to do the deeper holes as well as the cheap route through your
early units is to drill suitable 1/4" holes, broach them using a medium
arbor press. Any tool and die house can make a simple piloted broach
that fits into a piloted base plate. You only have to do 1/4 of the cut
per pass if you want to do it manually.

wrote:

DanG wrote:

Go to any one of their pages under the "Punching" heading. Scroll
to the bottom of the page. There is a picture and sizes of the
punches that fit each particular punch. The very first page I
sent you told how to calculate the number of tons you would need
to accomplish your task.

http://roperwhitney.com/index.cfm

Put your mouse on the word PUNCHING in the black band under their
logo. Go to any one of their punches listed. Scroll to the
bottom of that page to see available punches and sizes.

Put your mouse on the words PUNCHES & DIES in the black band. Go
to the "determining tonnages" page.


Thanks.

The problem with all that is that mild steel is assumed, and I can only
assume that the charts at the bottom of those pages are showing numbers
like "1/8 - 17/64" to mean thickness - hole size, even though this
isn't clear.

Also, can anyone tell me what gauge("Ga") is equal to 1/16"?

Thanks.

Darren Harris
Staten Island, New York.