Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Gears
 
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I am thinking of making a machine that will punch a .375" max hole in .250"
mild steel. First of all I need to find out how much machine this will take.
Will a 50 ton hydraulic bottle jack have the power? Who sells the dies? Can
the dies be made?

Thanks,
Bill

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David Courtney
 
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We have several Unipunch tools... punch several 1/2" holes in 1/4" mild
steel at once, with a 60 ton Minster punch press. The 8AJ 1-1/4 list here
is rated for .4375" holes in 1/4" plate:
http://cgi.ebay.com/ws/eBayISAPI.dll...tegory=25 278
Specs are he
http://www.unipunch.com/pdf%20files/EuroVersion031.pdf
David


"Gears" wrote in message
...
I am thinking of making a machine that will punch a .375" max hole in

..250"
mild steel. First of all I need to find out how much machine this will

take.
Will a 50 ton hydraulic bottle jack have the power? Who sells the dies?

Can
the dies be made?

Thanks,
Bill

--
Advertise your metalworking stuff free he
http://www.wallenderengineering.com/class/index.php




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Grant Erwin
 
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Hoo boy. Ten tons would be overkill. Scotchman specs that at 7.4 tons. See:
http://tinyisland.com/punchtable.pdf

You can buy punches and dies from http://www.clevelandsteeltool.com that's
where I get all mine. They don't make real little ones. Be aware that you
need clearance punch to die. To make a precision hole, the punch is sized
exactly and used with an oversize die. To make a precision slug, the punch is
sized undersize and the die is exact. For ¼" mild steel, you will need about
1/32" clearance so don't order a ¼" die, order a 9/32" die.

It is possible to make punches and dies on a lathe. Make them from tool steel
and heat treat them after fabrication. The die needs to be a cylindrical hole
for only about 1/8" deep then the hole should open out in a conical fashion so
the slug can drop through. Pay attention to how you make the stripper for your
machine, this part is critical in actual use. Don't punch dry - use a high tech
grease, it will increase your tool life by a factor of 10 or more and it isn't
that hard to clean off after you're done. Centerpunch your hole locations and
feel the tit on the end of the punch with the stock and lower the stock with
the ram along with the punch until it engages the die, and you will be dead
on your center punch every time.

I'd call them and tell them you are fabricating a machine and ask them what
is the cheapest punch/die set cost of all the various types they stock. A set
for my Scotchman ironworker is about $21 for a punch and a die.

Punching beats the crap out of drilling.

Grant Erwin



Gears wrote:
I am thinking of making a machine that will punch a .375" max hole in .250"
mild steel. First of all I need to find out how much machine this will take.
Will a 50 ton hydraulic bottle jack have the power? Who sells the dies? Can
the dies be made?


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Ernie Leimkuhler
 
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In article , Gears
wrote:

I am thinking of making a machine that will punch a .375" max hole in .250"
mild steel. First of all I need to find out how much machine this will take.
Will a 50 ton hydraulic bottle jack have the power? Who sells the dies? Can
the dies be made?

Thanks,
Bill

--
Advertise your metalworking stuff free he
http://www.wallenderengineering.com/class/index.php



I rigged up punch and die holders for my 20 ton shop press.
I have punched holes with it, but in heavy materiel it is a bit scary.
The problem is OVER-TRAVEL.
The press frame flexes enough while the pressure loads that when it
finally punches through it slams the carriage into the materiel.
It releases the pressure in the bottle jack so fast that it seems to
foam the fluid.

Makes a scary sound too.

I can see building a big C frame punch, but I would use an actual
hydraulic cyclinder and pump.
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