Dies for press.

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Munty Scruntfundle

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HI there. I'd like to have a go at making some steel dies for my 2 ton press, nothing special, just some different angles, I have a half decent mill so that's no problem.

I'd like to harden the steel, I don't have a fancy oven, just a small torch, but I reckon as the parts will be small I should be able to get a uniform heat. Where I'm absolutely not at all sure what I'm doing, is choosing the steel I'll need. I understand from watching a few videos you can't really harden basic mild steel. But what's basic mild steel? There are no end of variations. Can any mild steel be hardened?

If I really need a carbon (or high carbon) steel, what variety should I look for? Again there are no end of variations.

Over to you folks if you don't mind, I need some advice!
Many thanks.
 
Plus one for case hardening - in fact I was just typing my suggestion when Dalboy's post popped up. It's simple to do at home and your dies could be made from mild steel, which makes for easier machining. Certainly worth a try, I feel.

G.
 
When it comes to hardening steel you need to look at the carbon content. Generic mild steel is 1018 for example. The 10 tells you it’s basic steel. The 18 tells you the carbon content. 18 is not enough carbon to harden. When you get to say 1095, you can really harden the stuff.

For dies, it’s not uncommon to use A2. I am not familiar enough to tell you the exact alloy. For home stuff with limited use, I would say something in the 1040 range should work. But the black smiths may have a better solution
 
I did just this in my apprenticeship when i had a 18 months in the tool room. It depends what you want out of your dies and punches and how many of what your making.
Our punches and dies where mounted on 1 1/2 metal plates top and bottom and they had ground and hardened steel pillars and sleeves. The punches were mounted on the top and bottom plates, the pillars kept everything in alignment. These tools would have made hundreds of parts, maybe more.
After you have hardened the punch and dies how will you sharpen them?
 
case hardening with casnite is one way another I came across is to plunge red hot mild steel into salt and let it cool and absorb the calcium CARBONate
 
Make the dies from the high grade carbon steel you can find.
Machine them as smooth as you can and to the final size.

The common way is to use Casmite Case Hardening powder. Heat to red heat and cover in the powder and repeat.
The cheep way is to make hardwood charcoal, grind into a powder, like a good coffee grind.
Heat to a uniform red heat and cover in the powder. Allow to cool, remove the surplus with a wire brush and repeat up to 4 times. I say 4 as thats how many I did.

Heating and plunging into Ice cold salt water will harden the steel, but it will need to be tempered.

Carbon enriching will not.
 
From my experience case hardening is more trouble, more expensive, and the results aren't as good as just buying and using O1.

Cromwell Tools Flat Stock

(Edit - Would a small case-hardened mild-steel die cope with up to 2 tons of pressure?).
 
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I'd def look at hardened Silversteel.....limited life remember....
there are a few places on the interweb that sell ready mades.......
I'm in the same boat needing a few but keep putting it off.....
Home made punches will need exra care/accuracy as any slight errors n gaps will end up jamming the material.....
like 3 phase electrics, punch and dies are a black art...
I'd just love a metal worker but not enough work for it anymore and I'm to old....
Munty....take 5 mins and look at what it can do.....my first experience with one was in S Africa 30 years ago...making security products....
they do come up on the web occ.........
Unknown-6.jpeg
 
If you use a tool steel (silver steel, guage plate etc.) and harden it it will be very hard but very brittle. For a die it is very likely to crack (think glass).
You will need to temper the steel once it is hardened. To do this you will need to heat it up to a lower temperature and then let it cool down slowly this will softne the metal a little but make it tougher. Around 280 deg C is the temperature I would use. This can be done reasonably simply. First polish the metal with emery paper so you can see its colour, surround the part with fireprrof bricks (Lightweight insulation blocks work well), then heat it until it turns mid brown (google temper colour chart). Stop heating and let it cool down slowly.

The advantage with case hardening is as the name suggests you only get a case of hard material (typically a fraction of a mm) so the tool stays tough as it is mild steel but resists wear due to the hard case. Typically you would not temper case hardened tools so you have a glass hard surface.
 
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