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-   -   Hydraulic Press Saftey (http://www.knifenetwork.com/forum/showthread.php?t=70006)

Ed Caffrey 09-17-2021 01:36 PM

Hydraulic Press Saftey
 
OK... I've preached it for years and years, and have witnessed it a couple of times first hand...

IF YOU ARE GOING TO BUILD/USE A HYDRUALIC PRESS FOR FORGING, DO NOT CHEAP OUT ON BUILDING IT, AND ESPECIALLY DON'T CHEAP ON ON THE CYLINDER... AT LEAST 5" IN DIAMETER, AND BETTER YET.. 6"!!

Why? LINE PRESSURE! The smaller the cylinder diameter, the higher the required pressure to gain tonnage (how hard it actually presses down). Anything over 2500psi is TOO MUCH! Yes, typical hydraulic lines are rated from 3,000 to 4,500 psi.... but that is best case scenario, and not the torturous use and environment that forging presses sees, along with the spikes in pressure that occur simply by the way a forging press is used.

If you want to roll the dice or play the odds... you should look at this before doing so....

https://www.mfcp.com/our-blog/bid/39...ction-injuries

If you screw around and try to build/use a forging press with a small cylinder...its not gona be IF.... it's gona be WHEN. Nuff Said!

KenH 09-17-2021 02:57 PM

Ed, you're right of the need for a 5" or 6" cylinder if the desire is for a 25 to 30 ton press. BUT - for those folks like me where a 12 to 16 ton press will do everything needed for forging, a 4" cylinder works and is a good bit less expensive. Heck, even that 8 ton I got from Coal Iron was pretty good by using small 1.5" wide dies. Their claimed 12 ton with a 1.5" wide die is putting more pressure (per sq in) on a billet than a 25 ton press with 4" wide dies. Isn't that a valid statement - what counts is pressure per sq in.

If the max pressure "safe" is considered to be 2500 psi a 4" cylinder gives right at 16 ton. 1900 psi (and should be very safe) will give right at 12 ton.

While tons is easy to calculate with (cylinder area X psi)/2,000, this site is an easy tonnage calculator: https://www.baumhydraulics.com/image...s/cyl_calc.htm

These hydraulic systems that run 10,000 psi just plain scare me to death! The only reason I'd want the 4500 psi rated hydraulic hoses is for the safety margin because I ain't planning to run anywhere near that kind of pressure.

Ken H>

Ed Caffrey 09-19-2021 02:45 PM

I totally agree with you on how the die size(s) impacts the pressure/tonnage applied to a work piece. There are many variables that can come into play with a press. Even with Orange Crush (my 80 ton press) there are times when I am working on very large billets, with a lot of surface area, that even it has difficulty moving.

Your mention of those folks who don't need anything overly large, is absolutely valid too. I know for myself, the size of steel I work, and/or Damascus billets I create, have always been limited by the size of my equipment. For years I used a "C" frame press that put out 24 tons. It was limited to a starting billet of 1" wide x 4" long X 25-30 layers. That was also about the biggest billet I could fit into my (then) welding forge. As time passed, and particularly when I got my hands on Orange Crush, it gave me that capability to start with billets of 1 1/2" wide X 8" long X 50-60 layers. That in turn, forced me to enlarge my welding forge to accept at least those size billets....
Condensed version....most of use will work within the limits of our tools.

All that being said, there is still a huge portion of folks out there who simply have not idea of the forces they are dealing with, are using something they call a "forging press", that is just waiting to blow up in their face(s).

All I'm saying is be aware of the dangers of the tool(s) you are using, and do your best to mitigate those dangers. The moment you loose respect for any tool, that is when it will "get you". BE SAFE! I'd much rather be talking too a person, than about them. ;)

KenH 09-20-2021 09:50 AM

Quote:

Originally Posted by Ed Caffrey (Post 501920)
The moment you loose respect for any tool, that is when it will "get you". BE SAFE

Boy, that sounds like riding a motorcycle! Rode bikes as basic transportation (20k+/yr was normal) for over 60 yrs - they will get you!
Quote:

Originally Posted by Ed Caffrey (Post 501920)
I'd much rather be talking too a person, than about them. ;)

talking to you rather than about you - I love that phrase.

Hang in there Ed.


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