Die Material

[jmeineke]

I've been making some copper beads using mild steel dies (hot rolled) in a guillotine tool and I'm a little surprised at how quick the top die is mushrooming. I'm hitting a lot harder on the one side because I'm drawing out some copper stock (the die has three different functions).

Should I be using a different material? How do you deal with the mushroom effect? Is there any saving these dies, or do you just use them till they wear out?

Sorry if this has been covered before, but I've turned up a blank in my searches.

[Timothy Miller]

Forge and grind the die back into shape and super quench the top die. The next step would be to get some alloy steel to make the die from 4140 is my personal favorite. Old road grader blade works too but finding the right heat treatment can be tricky.

[pkrankow]

Many dies in a guillotine have a "button" or slug of steel welded to the top of the die for the hammer to strike. This prevents the die itself from taking so much damage, and in the case of highly hardened dies, provides a softer steel for the hammer. In your case it will distribute the load some to prevent your softer dies from being smashed.

I agree with southshore, draw out the damage, clean it up, and possibly superquench the die. Welding the button can be done after, just wrap the working end of the die in wet rag before welding. A 2 inch cube (or cylinder) of mild steel should be fine, something harder may last better, but considerably softer than a hammer face.

I'm not an expert here, just telling what I have seen. Someone with more experience please weigh in.

Of course using a better material in the first place would be better.

Phil

[dkunkler]

Using a heavier hammer may also reduce the mushrooming.
A slow speed blow from a heavy hammer gives more of a "push" effect. With sharp raps of a lighter hammer more enery is absorbed near the point of impact spreading the metal of the tool.

[thecelticforge]

Using a heavier hammer may also reduce the mushrooming.
A slow speed blow from a heavy hammer gives more of a "push" effect. With sharp raps of a lighter hammer more enery is absorbed near the point of impact spreading the metal of the tool.

You may also wish to use a softer hammer such as persimmon, or the base of a dogwood tree.

[jmeineke]

I didn't know hot-rolled could be hardened - I thought it was just 1020. Is that not the case?

[pkrankow]

I didn't know hot-rolled could be hardened - I thought it was just 1020. Is that not the case?

Superquench. The most aggressive quench easily available. You are right, 20 points of carbon isn't much. A36 _may_ have up to 40 points of carbon though.

http://www.anvilfire.com/FAQs/quenchants.htm

May be more effort than it is worth though. Are the die faces holding up?

Phil

[John B]

I've been making some copper beads using mild steel dies (hot rolled) in a guillotine tool and I'm a little surprised at how quick the top die is mushrooming. I'm hitting a lot harder on the one side because I'm drawing out some copper stock (the die has three different functions).

Should I be using a different material? How do you deal with the mushroom effect? Is there any saving these dies, or do you just use them till they wear out?

Sorry if this has been covered before, but I've turned up a blank in my searches.

Good advice already, this is my take on the situation.

Clean off damaged face/end and weld a striking button on to the top, then harden the working surface when you are happy with the fucnction of the tool, Ideally make the dies out of a tool steel if you can for longevity, in practice mild steel stands up well in use.

To harden the working face only on the dies, toxic fumes and all probably, (I don't know the chemistry of this, but I do it in a well vented area and try to keep away from the fumes just in case) I am not recommending this but it works for me, I heat the working areas up to bright red and immerse/dip the working area in ordinary table salt in a container, I do this a couple ot times, the salt attaches itself to the workpiece and becomes liquid, when I am satisfied with the coverage, I rapid quench in clean cold water. The metal is appreciably harder on the surface and will wear better, this is probably equivelant to your superquench.

Personally I prefer a top and bottom die that does one operation rather than trying to make a progression or multi function tool that requires the work to be transferred laterally across the tool faces as there is a 'crabbing' effect as the force is not transmitted in a vertical manner.

Your tool is in effect getting three times the usage as a single tool, and is also coining out at each operation stage, so is more likely to show wear

This is a picture of top and bottom dies I use to produce a 6mm (1/4")round bar, you can see the striker button on the top tool. No particula r reason it is hexagonal other than it was what I had spare in the offcut bin at the time I made the tooling, and it is disposable/replacable.

[jmeineke]

Thanks - this has all helped a lot.

Phil - no, they aren't holding up so well. That's my fault, though; I'm not doing this right, but on the upside I'm learning a lot.

[pkrankow]

Thanks - this has all helped a lot.

Phil - no, they aren't holding up so well. That's my fault, though; I'm not doing this right, but on the upside I'm learning a lot.

After cleaning up the dies, then maybe a try at superquench is worth the effort. There is an alternate recipe that uses Jet Dry instead of shakalee 1.
http://forums.dfoggknives.com/index.php?showtopic=5750&st=20

You can always give this a go after you the dies working about how you want them.

No, I haven't tried it myself yet.

Learning is good!

Phil