## Friday, April 7, 2017

### Tonnage Calculation

A common question.. Does my machine have enough tonnage to punch the hole my job requires?

Lucky for you, we have a tonnage calculation to answer that question!

Let’s say your machine has a 50-ton capacity and you need to punch a 5/8” round hole through ½” A-36 mild Steel. Using the formula LTS/2000 we can calculate the tonnage.

L= Length of cut in inches (use circumference [π x diameter] for rounds and perimeter for other shapes)

T= Thickness of material in inches

S= Ultimate shear strength in pounds per square inch (PSI)

 1.963 X .500 X 60,000 = 29.45 tons 2000

This means to punch a 5/8” hole in ½” thick material it will take 29.45 tons, since you have a 50-ton machine there’s enough tonnage to punch the hole.

Punching different materials means there are different shear strengths. To keep it simple we have come up with multipliers to calculate tonnage when punching different types of material.

If you’re punching the same application but with a different material type, a quick way to calculate the tonnage is by multiplying the tonnage by the multiplier in the chart below.

Example with stainless steel: the shear strength would be 70,000 PSI and from the chart below we see the multiplier is 1.17. Therefore, we take the tonnage from before times 1.17:

29.45 tons X 1.17 = 34.46 tons required to punch stainless