Just to add my pound of nonsense to everyone else's advice.
- a) are the punches referenced so often simply a tool steel ground to
- purpose? i.e. can I buy graver blanks and grind them to shape for
- purpose of punches?
That would be a complete waste of a graver.
All you need is a length of hardenable steel.
Most of the WKMG uses "drill rod", Emerich likes old files,
but I tend towards buying the harbor freight letter punches,
and grinding them down. They can be a heck of a deal at times.
Sometimes they are water hardening, sometimes oil hardening.
- b) will mild steel work for silver/gold striking? Annealing,
- then hardening tool steel is a bit beyond me, I'd like to just carve
- and go.
Yes it will, we only harden our dies for really major orders, but
NO IT ISN"T BEYOND YOU.
Heck it is EXACTLY what you are going to do to make punches isn't it???
- c) I've seen pictures of a 16th cent English screw press for
- "striking" the coins, will you respect me in the morning if
- hit the blank with a hammer?
No we won't respect you. We might lure you down a dark alley,
smack you up side the head, and steal your press, and then
tell you it must have fallen out of your pocket while your wern't
looking. But we are only doing this with your best interest at
- Raymond apparently as Kristin Johnsen wrote
- ["Use "cold rolled" as the process of forming them
under pressure while "cold" compresses the metal crystals and
adds at least 50% strength over "hot rolled". ]
This is a bit misleading. Since you generally will anneal the punch
face as a first step, it will (in that area) be no stronger that the same
steel in a dead soft condition, and it will be in this state at least
into the region where you see the temper colors on your rod or punch
- Cool most of my questions are answered with this. Drill rod and
- Cold rolled steel I can get from OSH (Orchard Supply Hardware). I
- "think" they might carry the larger diameter, around 1
- rolled round stock which would make good inexpensive beginner
They do carry them, but they certainly make you pay for that.
I think) is usually cheaper (a lot) and
and frequently has free shipping on orders over $50.
I recommend the use of drill rod, from the get-go.
It doesn't rust as badly, and is ground to dimension, so it 's size is
Cold rolled is good, but not as good, and is not always round.
[Osh or whoever they seem to get it from usually uses a bar cutter to
size their stock, which mangles the ends.]
Hot rolled is the worst, and I don't think it is worth the
Then you said
- Then I start pricing out the cheating method of 20 ton arbor presses
Think more like 100 tons
- Oh, the bottom die. Shouldn't that be resting on wood or leather?
- We have a 35lb anvil at work but I don't want to mess it up
- mashing hard steel into its very nice surface.
I didn't see that anyone else addressed this. For several reasons,
not only no, but hell no.
Good hard wood would not be too bad, but you will just cut
through the leather. Part of what you are doing when you
strike, is generating a pressure wave that travels down through
your dies. When this reaghes you bolster/anvil/ground, part of it
substantially increasing the forces at the die face. The bigger ,
heavier, and harder a surface you strike on is, the more of this
reflection you get.
Imagine if you will, trying to strike with the die sitting on foam
I would not use your nice anvil. GO to harbor freight, and get one of
[Anvil like objects] Sit that on a good chunk of wood, and you will be in
Drill a hole the size of your die, about 2" deep into the ALO, [Some
where between its feet]
and then a 3/8" hole all the way through. This is what the WKMG
"bolster" for some reason lost in the mists of time. The one we
use is probably > 50 lbs,
but the one I use to teach at pennsic are only 5 and 15 lbs, but I would
use bigger if I had it.
- My impression is that a cast iron press frame is really necessary.
There is no inherent engineering reason why this is so.
In fact if a new one were being made these days, I would
expect that it would be made from a laminated stack of stampings.
- It's possible to build a screw press by making a frame of
welded structural steel, but I'm guessing that, unless it's massively
overbuilt, the forces involved would distort it pretty quickly.
Not really. It doesn't need to be overbuilt, just properly built.
BUT it would be massive.
Calculate the peak forces you want to generate, and make
sure you don't begin to approach the yield point.
Now drop hammers are another whole alternative, and
are really nothing more that a free falling hammer.
I know they work, and work well.
Treadle hammers are probably even better.