punch press / power press tonnage rating

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ecdez

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I've been eyeballing a power press that there is very limited information to on the internet. It looks like a large punch press with the exception of a jack shaft that appears original as it's cast into the body. It's called a number 10 and my first thought is it's a 10 tonner but I have no basis for this assumption. Are they normally numbered as their ton rating?
 
Depending on the brand, the 10 on it could mean 10 ton. I'm trying to find a chart of crankshaft size vs tonnage.

An approximation of tonnage:

Tonnage = K(d^3) / Stroke


where d = crankshaft diameter (inches), K is a constant, 3.4 for open front presses, 5.5 for double sided presses, 3.5 for eccentric presses.
 
Here's a picture. It's a Stiles & Parker. I've got two smaller punch presses that are of similar construction and I don't know the tonnage on them either so the formula above will be helpful; thanks!

I imagine this, as well as my others, classifies as a eccentric press.


Would crankshaft diameter be measured at the flywheel or at the arm (not sure the correct terminology, but I'm talking about the item in the middle that is connected to the eccentric portion of the crankshaft)? They appear to be different sizes.


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I think you measure the crank diameter at the main bearings. It looks like the left end of the crank is the same diameter as the bearing journals. Just my overall impression of the pictures, is that the press would be in the 10 to 15 ton range, depending on the stroke. It looks to be about a 2 inch stroke. Looks like a very well made press.
 
X2. 10 Ton is a good assumption based on the photo, model # and what Ive seen working on my share of old mechanical punch presses.
 
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Quite frequently they do get their model number from estimate available tonnage. When you turn ot on does the punch start going up and down by itself?

Bob
 
Rbeckett said:
When you turn ot on does the punch start going up and down by itself?

Bob
Click to expand...


No, it's got a foot pedal. You can see the cable to it in the last picture.


Cheeseking said:
Pretty neat if ya ask me
Click to expand...

That's part of the reason I'm looking at it. Not sure if I'm up for a 6 hour round trip though. I've already got two but didn't know the ton rating on either of them.





I think I'm doing my math wrong. I've got a 1.125" shaft on the one below with .68" of travel and my math comes out to 7.23t but it looks pretty small to me..



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This one has a 1.5" shaft with 1.15" of travel and maths out at 10.27t. This one might be plausable.

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Any thoughts?
 
From what I could find it is a 10 ton press. Weights about 500 pounds.
 
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