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

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

If you need assistance, please contact our Green Team 7 am to 6 pm

Friday, January 20, 2017

Punching Angle

Punching holes in angle can be quite challenging if the die block on your machine is nonadjustable. Luckily for you, we have the solution!

Click to Enlarge

Offset punches with matching offset dies solve this problem and allow you to punch closer to the inside leg of angle iron. The punch is machined offset based on the body diameter of the punch and size of the hole. For example, if you're using a F-16 punch (1-1/16 body) and punching a 1/2" offset hole, the offset will be .281". (See drawing). The die will be offset .281" as well to match the punch. The tooling is inserted in the machine the same as a standard punch and die.

We manufacture offset punches and dies for every ironworker to make your job easier. Have questions? Contact us anytime to see how offset punches and dies can help your production! We can be reached at or by phone at 
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Thursday, December 15, 2016


Must watch! Neil's passion and work ethic for fabrication is inspirational!

Tuesday, December 6, 2016

Fabtech 2016 Highlight Video

Check out this highlight video from Fabtech 2016!

Wednesday, November 9, 2016

Lancing Punch

In this application, the customer required an elongated D lancing punch. Lancing is defined as a process where material is sheared and bent to make tabs, vents and louvers. During the process, there's no material removed, it is formed into the shape required. The customer requested a 13/32" x 1-19/32" tab to be generated. We machined a blend radius on the rectangle end of the die to prevent the material from shearing. The angle of the tab varies depending on the stroke of the punch. 

Check out the pictures and video to see how the tooling and finished product were used!

Monday, November 7, 2016

Cleveland Indians

We already can't wait for the next Indians season here at CPD!

Friday, October 14, 2016

Custom Gum Drop Punch

Our customer needed to manufacture gum drop shaped tabs with ½” holes using their Marvel MSIW60D ironworker. Our engineering team determined a two-step operation would be necessary to produce these tabs.

The first operation included manufacturing gum drop shaped tooling to fit the oversize attachment. The punch was machined with a flat face and we used .028” clearance to ensure each tab would be free of any distortions. Lastly, it was critical to machine a 1/4“x1/8” keyway on the punch and whistle notches on the die to provide proper alignment during the punching process.

To begin the second operation, we replaced the oversize attachment with the standard attachment for punching the ½” round holes. This is an easy switch and tooling is more cost effective. We designed a die with 3 alignment pins to guarantee the hole would be punched in the same position on each tab.

The customer will weld these onto their product and utilize the round holes for bolts.

Need tooling for a similar application? Send us a picture or drawing and we can make it happen!