What steel to use for dies to heat treat?

steveonmars · Dec 27, 2019

I need to make some dies for a couple small punch presses I just bought. The presses are half ton bench top models so not a lot of pressure. What the dies are for is bending 1/4" mild steel wire. The dies will be approx. 3" on all sides with mounting flanges and grooves cut into them for bending the wire into different shapes. I can make the dies with no problem but I don't know what would be the best steel to use. I'm not really set up to do the heat treating myself unless it's very simple so I'll probably find someone locally to do that unless you guys have something better. I don't see why the dies need to be heat treated all the way through so I think just having them case hardened will work for what I'm using them for but I don't know what option will be not only best but cost effective (small home shop, small budget). Any advice would be appreciated.
Thank you

plastikdreams · Dec 27, 2019

D2 or s7...a2 would work too.

MattiJ · Dec 27, 2019

steveonmars said:
I need to make some dies for a couple small punch presses I just bought. The presses are half ton bench top models so not a lot of pressure. What the dies are for is bending 1/4" mild steel wire. The dies will be approx. 3" on all sides with mounting flanges and grooves cut into them for bending the wire into different shapes. I can make the dies with no problem but I don't know what would be the best steel to use. I'm not really set up to do the heat treating myself unless it's very simple so I'll probably find someone locally to do that unless you guys have something better. I don't see why the dies need to be heat treated all the way through so I think just having them case hardened will work for what I'm using them for but I don't know what option will be not only best but cost effective (small home shop, small budget). Any advice would be appreciated.
Thank you

Anything from 1018 to 30lbs chunk of carbide depending how many parts you want to form per die. Five, thousand or 20 million parts?

A2 would be easily available and forgiving to heat treat with good dimensional stability.

Prehardened mold steel would let you skip the hardening, something like Toolox 44 would probably last hundreds or thousands parts.

steveonmars · Dec 27, 2019

I make roughly 1000 parts a week. I thought about the prehardened steel but don't know how much harder that is to machine. I don't have a mill so I'll be doing the machining by simply drilling holes into the blocks and cleaning out the excess with a grinder and hand tools. These don't have to anything with close tolerances as long as they bend the wire in the right shape. The top dies will just be something that goes into the groove enough to bend the wire.

plastikdreams · Dec 27, 2019

MattiJ said:
Anything from 1018 to 30lbs chunk of carbide depending how many parts you want to form per die. Five, thousand or 20 million parts?

A2 would be easily available and forgiving to heat treat with good dimensional stability.

Prehardened mold steel would let you skip the hardening, something like Toolox 44 would probably last hundreds or thousands parts.

Well if we are going exotic, let's just go cpm10 or 15v

Mtndew · Dec 27, 2019

steveonmars said:
I thought about the prehardened steel but don't know how much harder that is to machine.

Not as hard as some people make it out to be, we cut tons of pre hard steel, you just need to run a little slower than 1018 maybe 25% slower to start and adjust from there.

Onepass · Dec 27, 2019

I’m sorta retired now, but I know some of the old timers years ago would refer to 4140 or 4340 pre hard as brake die. I know we kept viscount 44 as an” emergency “ die material. It is just a 4340 that is hardened to about 44 Rockwell C scale. It’s hard enough to make a part that will work for a while as a quick fix for a busted die or a tryout piece that you can use for a while without sending out to get hardened. You can still machine and drill it with regular drills, but it is tough shit and slow going! 4140 pre-heat is only about 20-25 Rockwell, but for a simple die that is a definite step up from cold rolled, it’s not too bad and a lot easier to machine. Different vendors of steel have different names for their 40-45 Rockwell chrome molly steel- just have to ask them!

steveonmars · Dec 27, 2019

Thanks so far for the help. I was a machinist, ended up doing mostly programming and set ups until I got hurt 20 years ago so I forgot more than I remember! I made dies but never got into the different steels enough to remember what works where. Any advice on how hard these dies should be when they are done so they last a long time? That'll help me decide whether to go with prehardened or something milder that I get hardened later, or will the prehardened have to be hardened even more for a long lasting die? If I go with a prehardened 4340 will that be hard enough for what I'm using it for?
Thanks again

AARONT · Dec 27, 2019

If you're wanting these to last for a long time, I would go with DC53 hardened to a 58-62Rc. It's fairly stable at heat treat and basically has the best properties of D2 and A2.

steveonmars · Dec 27, 2019

I looked up dc53 and that sounds perfect. I just need to find out what it costs and where to get it

AARONT · Dec 27, 2019

Give your Alro Steel rep a call. I order it though Alro.

For any other difficult to find tool steels, I have used International Mold Steel. Welcome to International Mold Steel

steveonmars · Dec 27, 2019

Thanks I did see them but didn't go to their site yet. Thanks everyone for the advice

MattiJ · Dec 27, 2019

steveonmars said:
Thanks so far for the help. I was a machinist, ended up doing mostly programming and set ups until I got hurt 20 years ago so I forgot more than I remember! I made dies but never got into the different steels enough to remember what works where. Any advice on how hard these dies should be when they are done so they last a long time? That'll help me decide whether to go with prehardened or something milder that I get hardened later, or will the prehardened have to be hardened even more for a long lasting die? If I go with a prehardened 4340 will that be hard enough for what I'm using it for?
Thanks again

If you are just bending mild steel wire to funny shapes the mold is not much stressed at all. Without having a any clue what you are actually forming its hard to say how much stress and wear the mold or form is going to experience. Have you tried to make the mold from "ordinary" structural steel and if yes how long it lasted in the use?

Matt_Maguire · Dec 27, 2019

If your forming 1/4” rod, most used to use one of the various .5-ish carbon flavors sold for press brake die use. These could be used “as machined” to prove the shape & suitability and later easily flame hardened on the work surface if wanted.

Notable suspects were Bethlehems’ “Brake Die”, Crucibles’ “Maxal 3 1/2 and Hy-Tens' “Break Die” or “Flame Die”. The next level up would be L6 tool steel from various folks.

Crucible Selector - MAXEL® 3-1/2 (Brake Die)

Good luck,
Matt

Mtndew · Dec 27, 2019

steveonmars said:
Thanks so far for the help. I was a machinist, ended up doing mostly programming and set ups until I got hurt 20 years ago so I forgot more than I remember! I made dies but never got into the different steels enough to remember what works where. Any advice on how hard these dies should be when they are done so they last a long time? That'll help me decide whether to go with prehardened or something milder that I get hardened later, or will the prehardened have to be hardened even more for a long lasting die? If I go with a prehardened 4340 will that be hard enough for what I'm using it for?
Thanks again

You probably won't be able to do 100k parts with 4340pht but not seeing your application I could be wrong.
If you want something to last and machines rather easily, I suggest A2. Just don't try to cut it like it's 1018. But at least it cuts better than D2.

rogertoolmaker · Dec 27, 2019

steveonmars said:
I need to make some dies for a couple small punch presses I just bought. The presses are half ton bench top models so not a lot of pressure. What the dies are for is bending 1/4" mild steel wire. The dies will be approx. 3" on all sides with mounting flanges and grooves cut into them for bending the wire into different shapes. I can make the dies with no problem but I don't know what would be the best steel to use. I'm not really set up to do the heat treating myself unless it's very simple so I'll probably find someone locally to do that unless you guys have something better. I don't see why the dies need to be heat treated all the way through so I think just having them case hardened will work for what I'm using them for but I don't know what option will be not only best but cost effective (small home shop, small budget). Any advice would be appreciated.
Thank you

Use D2 for die wear. Heat treat to 62-64 Rockwell C. Build a die that will stay with you. I worked as a Diemaker, Tooling and Manufacturing Engineer and Die Designer for about 40 years. Your getting both good and bad advice. Your 1/2 ton punch press is to light to form 1/4" dia. steel rod. If you expect to form consistent parts your going to need at least a 12 ton press. You could also build a hydraulic forming fixture using form blocks. For best results send your tool steel to a heat-treater that has the proper equipment to do it right. Your going to spend time, money and effort so lets do it right the first time.

All the best,
Roger, 12/27/2019

implmex · Dec 27, 2019

Hi All:
To those who are advocating sophisticated steels and sophisticated heat treat, I think it might be worthwhile to keep in mind that the OP doesn't even have a milling machine to make these.
Here's a quote from post # 4:
"I thought about the prehardened steel but don't know how much harder that is to machine. I don't have a mill so I'll be doing the machining by simply drilling holes into the blocks and cleaning out the excess with a grinder and hand tools."

This to me, implies that this is never going to be a setup that can justify getting too elaborate with the materials and heat treat.
If the OP takes simple 4140 lumps, carves out his shapes with drills and a die grinder; gets them so they bend his wire how he likes it and then flame hardens it with a torch, it'll run like a bunny for a gazillion years.

Making them the way a toolmaker would make them is not an option simply because the OP doesn't have the gear to build them this way.
So the tool steel chosen will be a relatively minor part of the project in my opinion.

Buy something cheap and readily available.
Harden it with a torch.
Move on and stamp your parts.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

fciron · Dec 28, 2019

I'm in agreement with Marcus, KISS is definitely the priority here.

In my blacksmith shop I have some press dies for bending curtain rod brackets that are mild steel treated with case- hardening compound (Cherry Red from Mcmaster Carr) which have served me well for years.

I also use a lot of 1045, both as forged/machined and heat treated. (I have a good supply and it's easy and forgiving to heat treat). For bending mild steel you really just need the die to be harder than the part. There's minimal sliding or other wear to the die.

Mike1974 · Dec 28, 2019

Where in FL are you? We have one of these local to me..

Alro Metals Outlet - Clearwater (Tampa) Florida

They could get you some 4140 ph or A2/D2/H13/ whatever...

4140ph would be my first choice given your limitations, but A2 or D2 will likely last the entire life cycle of your parts, if you are willing to send it out for heat treat....

plastikdreams · Dec 28, 2019

implmex said:
Hi All:
To those who are advocating sophisticated steels and sophisticated heat treat, I think it might be worthwhile to keep in mind that the OP doesn't even have a milling machine to make these.
Here's a quote from post # 4:
"I thought about the prehardened steel but don't know how much harder that is to machine. I don't have a mill so I'll be doing the machining by simply drilling holes into the blocks and cleaning out the excess with a grinder and hand tools."

This to me, implies that this is never going to be a setup that can justify getting too elaborate with the materials and heat treat.
If the OP takes simple 4140 lumps, carves out his shapes with drills and a die grinder; gets them so they bend his wire how he likes it and then flame hardens it with a torch, it'll run like a bunny for a gazillion years.

Making them the way a toolmaker would make them is not an option simply because the OP doesn't have the gear to build them this way.
So the tool steel chosen will be a relatively minor part of the project in my opinion.

Buy something cheap and readily available.
Harden it with a torch.
Move on and stamp your parts.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

That info was provided after the original query. When I saw that I realized this wasnt a normal die making excursion.

What steel to use for dies to heat treat?

Plastic

Diamond

Titanium

Plastic

Diamond

Diamond

Hot Rolled

Plastic

Stainless

Plastic

Stainless

Plastic

Titanium

Stainless

Attachments

Diamond

Cast Iron

Diamond

Stainless

Diamond

Diamond

Similar threads