This article will describe what tonnage is and how to calculate how much you need.

If you are punching through anything other than mild steel or would like to use our Tonnage calculator, click here

What You Will Need

To begin, you will need a machine of some sort. Depending on the job you need accomplished, there are a variety of machines ranging from hand lever mechanical style to hundreds of tons using hydraulic pressure. You might be asking, “what is tonnage? and how much do I need?” We have the answers.

Tonnage: The amount of force a machine is capable of applying to a specific task.

Use the following formula to calculate the tonnage required to punch a round hole in mild steel:

Punch diameter x Material Thickness x 80 = Tons of pressure required

Example: to punch a 1/2″ hole through 1/4″ thick mild steel

0.500 x 0.250 x 80 = 10 tons required

Use the following formula to calculate the approximate tonnage required to punch a shaped hole in mild steel:

1/3 Perimeter of punch x Material Thickness x 80 = Tons of pressure required

Example: to punch a 9/16″ x 1″ hole through 1/2″ thick mild steel

Find perimeter: 0.5625 + 0.5625 + 1.000 + 1.000 = 3.125

Find 1/3 perimeter: 0.33 x 3.125 = 1.031

1.031 x 0.500 x 80 = 41 tons of pressure required

NOTE: The thickness of the material should not exceed the punch diameter.