Hardfacing (sort of)...

[Trip59]

I need to make a set of dies to be used in a press. They'll basically be for dimpling stainless steel. Being broke, and cheap by nature, it occurred to me that plain old mild steel will hold up fine, but I don't want the face to distort over time (this hopefully will be a production tool, used repeatedly, not a one-off) Now, the catch. I do NOT have a toolpost grinder, and the contour is trickier than I'd like to do by hand while spinning on a lathe. Any recommendations for a filler rod (TIG) that would offer fair resistance, or a stick rod that can be machined, yet wear better against stainless than mild steel?

My thought was to face it with a 300 series TIG filler, decent thickness (3/32 thick, post machining) which would work harden before it distorts unacceptably. Thoughts?

[sportbike]

I need to make a set of dies to be used in a press. They'll basically be for dimpling stainless steel. Being broke, and cheap by nature, it occurred to me that plain old mild steel will hold up fine, but I don't want the face to distort over time (this hopefully will be a production tool, used repeatedly, not a one-off) Now, the catch. I do NOT have a toolpost grinder, and the contour is trickier than I'd like to do by hand while spinning on a lathe. Any recommendations for a filler rod (TIG) that would offer fair resistance, or a stick rod that can be machined, yet wear better against stainless than mild steel?

My thought was to face it with a 300 series TIG filler, decent thickness (3/32 thick, post machining) which would work harden before it distorts unacceptably. Thoughts?

How are you going to finish the part? I am confused in that you say you don't have a toolpost grinder, but it is trickier than you want to machine by hand in the lathe, but then you want the material to be machined.

If it is too tricky to machine, then I am not sure I see how a tool post grinder or a machinable material will make it not too tricky to machine

You could just use a higher tensile strength filler rod to put material where needed. Something 80-100ksi would still be machinable.

[agent4573]

If its going to be a production die, don't cheap out on it because it will only cost you more in the long run. If you can't do it by hand, hire out to a shop that has a CNC lathe and get it cut. Otherwise pony up the $$$, buy a toolpost grinder and do it right. How much time and wasted material are you going to use up trying to make it right the 5th time you have to attempt it?

[Rambozo]

I need to make a set of dies to be used in a press. They'll basically be for dimpling stainless steel. Being broke, and cheap by nature, it occurred to me that plain old mild steel will hold up fine, but I don't want the face to distort over time (this hopefully will be a production tool, used repeatedly, not a one-off) Now, the catch. I do NOT have a toolpost grinder, and the contour is trickier than I'd like to do by hand while spinning on a lathe. Any recommendations for a filler rod (TIG) that would offer fair resistance, or a stick rod that can be machined, yet wear better against stainless than mild steel?

My thought was to face it with a 300 series TIG filler, decent thickness (3/32 thick, post machining) which would work harden before it distorts unacceptably. Thoughts?

Why not just make it out of medium carbon steel then harden it after you machine it? Or if you want to use mild steel, just case harden it for some surface wear resistance.

[Trip59]

How are you going to finish the part? I am confused in that you say you don't have a toolpost grinder, but it is trickier than you want to machine by hand in the lathe, but then you want the material to be machined.

If it is too tricky to machine, then I am not sure I see how a tool post grinder or a machinable material will make it not too tricky to machine

You could just use a higher tensile strength filler rod to put material where needed. Something 80-100ksi would still be machinable.

Not too tricky to machine, I can grind out the tools from cobalt to machine it, I was wanting to stay away from a hardfacing alloy that had to be ground, rather than cut, as I don't have a toolpost grinder, and being two halves to the die pieces, they'd need to be more precise than holding a pea grinder to the piece (I've shaped lots of things that way...)

If its going to be a production die, don't cheap out on it because it will only cost you more in the long run. If you can't do it by hand, hire out to a shop that has a CNC lathe and get it cut. Otherwise pony up the $$$, buy a toolpost grinder and do it right. How much time and wasted material are you going to use up trying to make it right the 5th time you have to attempt it?

I can see no need to drop the cash on a 2-3" dia. chunk of tool steel (would be in the hundreds) when 1018 can be had for under $50 with spare stock for my bin. True, I could prototype in 1018 and produce the final tools in tool steel, but... getting a bit off track.

This will be used in a manual press, low speed, not concerned about heating during use, no concern about high impact, or the other issues one would encounter with an automated system. If there was, I'd suck it up and buy the tool steel.


So I guess what I'm at, is there an alloy anyone can think of which would not yield to stainless under pressure, yet will still be machinable in an as-welded state? Or would I be looking at a 'grind only' or 'anneal - machine - re-heat-treat' as my only option.

[Trip59]

Why not just make it out of medium carbon steel then harden it after you machine it? Or if you want to use mild steel, just case harden it for some surface wear resistance.

Was king of thinking of the facing more like a thicker case hardening...

Cost and availability are what lead me to the original question. I don't really have anywhere local to pick up less than full length stock... limited to what the small-order online suppliers have.

[Rambozo]

onlinemetals.com has small lengths of 4140 and 8620 for good prices.

Weldmetal machining is always a crap shoot as far as hardness if the part isn't annealed after welding. So much depends on how much heat went in, for how long and how it was cooled. I wouldn't even think about machining weldmetal without carbide or ceramic tooling. Cobalt just doesn't cut it. FWIW I have often clamped a die grinder to the compound to use as a poor man's toolpost grinder.

You could TIG it up with 4130 rod. That would require a preheat, weld, anneal, machine, then heat treat. Seems like a lot of work over just using the right material. Time is money, too.

[Trip59]

onlinemetals.com has small lengths of 4140 and 8620 for good prices.

Weldmetal machining is always a crap shoot as far as hardness if the part isn't annealed after welding. So much depends on how much heat went in, for how long and how it was cooled. I wouldn't even think about machining weldmetal without carbide or ceramic tooling. Cobalt just doesn't cut it. FWIW I have often clamped a die grinder to the compound to use as a poor man's toolpost grinder.

You could TIG it up with 4130 rod. That would require a preheat, weld, anneal, machine, then heat treat. Seems like a lot of work over just using the right material. Time is money, too.

Ok, that may work... looks like 4140 would put me out around $50, factor in the time savings and it'd be about even. Still a hell of a lot cheaper than the tool steel I originally priced. I do have some good quality carbide inserts, it'll be a bit tricky for some spots, I was hoping to use cobalt with a profile ground to make it a bit easier on some of the complex curves. I eliminated the punch aspect, so that makes it easier, rather I'll drill as a pilot for the dies.

Been lucky so far, haven't had an issue turning weld metal. Good setup, nice sharp tooling, proper feed and speed, etc.

A small aspect of this was the facing, I'm trying to get myself dialed back in on all the processes. Knocked out some mitered AL this weekend, bear of an extrusion, 1/16 sections leading into 1/16 webs, another gap, then a 3/8 thick section mating to 1/16... Wish I took pictures. Was quite satisfied with the end result and the shop owner, whose display case door it was is ecstatic. I'm nice and happy on steel again and fresh Al, cast is going to take some more playing. I think I got the 6011 figured out, you were right, way different with an inverter. Amazing how much I retained over 14 years, also amazing how much I forgot

This also applies to some other odd shaped pieces that may come up, I'll have to evaluate those on a one on one basis as to what alloy and process.

[sportbike]

Make sure the 4140 is Quenched and Tempered. Otherwise, it won't be much better than other steels if it is in annealed condition.

[sportbike]

If you have a torch, You could buy a piece of Air Hardenable tool steel in a 1" X 3" disc, weld it to a piece of mild steel bar, then turn it, and then eat it and air cool to harden.

McMaster Carr sells 3" X 1" disc as P/N 8443K51 for $15.50 each.
www.mcmaster.com

Speedy Metals sells it for $11.23 an inch.

The issue may be with tempering it as it may be too hard.

If you have an old oven with a self cleaning cycle, you could use 17-4ph stainless in the same manner. Heat to 850-900F for a few hours and oven cool and it will harden.

[DVA]

Carbon steels are typically have higher yield strength than 300 series stainless steels and will hold up much better for tooling applications. 400 series stainless is much harder with higher yield strength but not much benefit over many available carbon steel materials.
Are you worried about wear or worried about the die deforming?

Metals have the same material properties in compression and tensile loads as for yielding (the pressure the material will plastically deform or if you are not familiar with this terminology, this is where material starts to permeate deform). If you do not want the material to deform you need to make sure your yield strength is high enough for the application.

If you are looking for surface wear you can use Stellite hard facing material to hard face the tool.

[Trip59]

Carbon steels are typically have higher yield strength than 300 series stainless steels and will hold up much better for tooling applications. 400 series stainless is much harder with higher yield strength but not much benefit over many available carbon steel materials.
Are you worried about wear or worried about the die deforming?

Metals have the same material properties in compression and tensile loads as for yielding (the pressure the material will plastically deform or if you are not familiar with this terminology, this is where material starts to permeate deform). If you do not want the material to deform you need to make sure your yield strength is high enough for the application.

If you are looking for surface wear you can use Stellite hard facing material to hard face the tool.

Worried about the dies deforming over repeated use, not wear so much. These will be used almost exclusively on stainless sheet in 12-16 ga range, though not sure which alloy yet. This initial set will be two sizes, but I have several things that will be made and require similar processes in various shapes (if all goes according to plan) in the near future.

[DVA]

Worried about the dies deforming over repeated use, not wear so much. These will be used almost exclusively on stainless sheet in 12-16 ga range, though not sure which alloy yet. This initial set will be two sizes, but I have several things that will be made and require similar processes in various shapes (if all goes according to plan) in the near future.

Most sheet stainless is very soft, with a yield strength of about 30000 psi and a ultimate strength of 70000 psi. If you are just dimpling the material, I would go with the hardest material that you can reasonably machine and afford.

[performance]

Maybe I am trying to picture it in my head and am tired, but do you have an example? You can get different diameter tool steel rods at Fastenal. Do you have to have 3" in diameter? Why? If this is a "drum" rotating, does it really matter as you can put pressure from the top side with bearings to keep things in contact

[Trip59]

Maybe I am trying to picture it in my head and am tired, but do you have an example? You can get different diameter tool steel rods at Fastenal. Do you have to have 3" in diameter? Why? If this is a "drum" rotating, does it really matter as you can put pressure from the top side with bearings to keep things in contact

I'm sure there are tons of these on the market I could buy, but making them is part of the process for me, and the process of making them will yield information and learning to benefit other similar projects where I know there aren't the specific shapes/sizes I need 'off the shelf'

Think about the back of an oven, or washing machine, where there's a dimple to provide clearance for a screw head. Nothing fancy, pretty simple.

This is for a product I hope to start producing soon, but other products in the works will need specific and custom sizes I may not be able to find, so this first round is sort of a prototype in and of itself.

Bottom die will be static, steel located on a pin, upper die locate on same pin, attached to the ram of the press. Apply pressure, release and done. Striking would be more ideal, but the press will work well enough for what I'm doing.

[Rambozo]

I'm sure there are tons of these on the market I could buy, but making them is part of the process for me, and the process of making them will yield information and learning to benefit other similar projects where I know there aren't the specific shapes/sizes I need 'off the shelf'

Think about the back of an oven, or washing machine, where there's a dimple to provide clearance for a screw head. Nothing fancy, pretty simple.

This is for a product I hope to start producing soon, but other products in the works will need specific and custom sizes I may not be able to find, so this first round is sort of a prototype in and of itself.

Bottom die will be static, steel located on a pin, upper die locate on same pin, attached to the ram of the press. Apply pressure, release and done. Striking would be more ideal, but the press will work well enough for what I'm doing.

I made a similar punch and die to make rectangular dimples in stainless sheet (about 14-16 ga. as I recall) for heat riser block off plates for Oldsmobile V8s. The punch and die was just mild steel and used a small air over hydraulic piston pin press for power. Made a metric assload of those little plates and never had a problem with the tooling. If you don't go crazy with the pressure and have the proper clearance and edge radius on everything you should be fine. If you want to have your tooling punch the hole as well, you can always machine a place to install a commercial punch and die set in the middle of your dimple punch. Then it will be easy to replace just that part when it gets dull.

[Trip59]

I made a similar punch and die to make rectangular dimples in stainless sheet (about 14-16 ga. as I recall) for heat riser block off plates for Oldsmobile V8s. The punch and die was just mild steel and used a small air over hydraulic piston pin press for power. Made a metric assload of those little plates and never had a problem with the tooling. If you don't go crazy with the pressure and have the proper clearance and edge radius on everything you should be fine. If you want to have your tooling punch the hole as well, you can always machine a place to install a commercial punch and die set in the middle of your dimple punch. Then it will be easy to replace just that part when it gets dull.

Wow, ok. So you did nothing to the tooling, no facing, treating, anything else? Not sure if I'll reach a metric assload, or even an imperial assload, but there will be quite a few for sure if all goes as planned.

As far as the punching, I hadn't really thought about incorporating a punch and die, but drilling them shouldn't be too bad, simple jig and clamps and I can run through a stack at once, pre-braking, then set them up and press them after braking to shape.

Question, how many tons was the press you used?

[Rambozo]

Wow, ok. So you did nothing to the tooling, no facing, treating, anything else? Not sure if I'll reach a metric assload, or even an imperial assload, but there will be quite a few for sure if all goes as planned.

As far as the punching, I hadn't really thought about incorporating a punch and die, but drilling them shouldn't be too bad, simple jig and clamps and I can run through a stack at once, pre-braking, then set them up and press them after braking to shape.

Question, how many tons was the press you used?

For sheet metal if at all possible I would punch the hole rather than drill it. Getting a burr free hole in sheetmetal with a drill doesn't happen, and it's worse when you drill a stack. You will spend more time and aggravation deburring before the next step. Stainless leaves tough burrs. What size hole do you need? If you have the hole in and can run on a center pin, that will make alignment easy, if your dimple is circular. I had two pins for alignment but a pretty loose fit and no springs, because of the kind of press I was using. The press was an old piston wrist pin press that was retired when we switched to a rod heater for installing wrist pins. There were no labels left on it, and a quick search didn't turn up anything that looked like it. I'm sure it wasn't much considering the way it was made, figure max 10 tons, and probably a lot less. For this job it barely had to work, I would even say you could do it with a good arbor press. The pressure you will need depends on how much deformation your are looking for and how much you need to stretch the metal. If you can avoid sharp edges and steep walls, it will be easy to press and come out looking much nicer.

[cbmkr]

We used a lot of small one off dies for 16-22 ga sheet metal and used 1018,1044,1045 cold rolled steel to make the dies, on the smaller dies that got a lot of hard use forming hot rolled structural steel we had some of them sent out and had them heat treated just to give them some added protection. On our larger dies for our 12' press brake we used 1018 cold rolled to build stamping dies, one was 2" x 1" half round cold rolled bar attached to a piece of 3/4" x 4" wide 1018 flat bar, this produced a half round dimple 2" wide and 1" deep in 16 ga sheet steel 48-72" wide to produce grain bed and trailer sides. We also did the same for Dump Truck Beds stamping a 2" angle form into the sides in 7-10 ga sheet, a lot of these were 12' long. Our radius dies for our bed floors were made from DOM tubing in 2,3, and 4" radius sizes.The floor dies did 10 ga to 1/4" all made in house from cold rolled products.These larger dies were in use in our shop for approx 8 years before we sold our company without any problems or adverse wear.

[Rambozo]

I think I got the 6011 figured out, you were right, way different with an inverter. Amazing how much I retained over 14 years, also amazing how much I forgot

The 6011 finally "clicked" for me, too. I think I was fighting myself or something because now it seems much easier than a transformer box.