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punch force

Hi All; I'm looking at making a press that will crimp the end of a piece of 1/2 to

1 1/2 inch EMT ( Wall thickness ~0.065) flat and punch a hole for a carrage bolt. Is there any formulas to calculate the force needed to punch a 3/8 square hole in 2 pieces of 0.065" mild steel? Pat
Reply to
Pat Ford
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(.33x total linear outline of the square) x material thickness x 80 = tons of pressure

Reply to
Wwj2110

You can lower your pressure needs with an angle on the punch.

Reply to
Tom Gardner

Hi Pat - take a look at:

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The sheet on Cutting Tonnage or the Perf Pressure tab will help you figure this. Someone also mentioned shear angle, which will indeed make a major difference (reduction). As noted, if you know the cross sectional area it's pretty straight forward.

Later-

SMA

Reply to
Sean-Michael Adams

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