Press die - sheet metal, possible?

[Whiskeymike]

I’m looking to take a 16’’ steel sheet disc and press a .5-.75” flange around the circumference that is 45-90 degrees, similar to a pie pan. I’m thinking of cutting a bottom die from 1/4” plate stacked 3-6 high with, plus additional bracing. Then a top die from the circles cut from the bottom.

I have a 20 ton press that I’ll use to operate the dies.

Hoping to do 16 gauge, but could use 20 if I had to.

Think it’ll work without it coming out like a pringles chip? I’d like to get some thoughts from the more experienced before wasting a few hundred bucks on a sheet.

 

[ez-duzit]

Fuggetaboutit.

You could possibly spin it.

 

[Lwel9226]

Bead roller....

Lynn W

 

[matt_i]

There is no way. The metal has to be clamped around the perimeter for it to be stretched on the bend angle so it doesn't wrinkle.

When you bend this rim upward, a larger circumference has to become a smaller circumference.

 

[lilredex]

Try it with a smaller diameter first. I needed some of those rings that Mopars have at the fuel tank entry. They are 6" dia. and have about a 5/16" 90* lip.

I used a 6" solid steel plug and clamped it to another piece of steel, then hammered over the lip. Bending it up slowly allowed the lip to shrink at the same time. It was trimmed as needed afterwards and the center was cut away. It looked like a factory job after it was completed. Material was 18Ga.

You could also use hardwood as a form.

It was the ring that sat in the round recess shown here.

 

[Sliceddeuce]

Making one piece?? MDF hammer form. www.metalmeet.com

 

[bigguns69]

What you are talking about is a forming die, similar operation to what is done for discs for a two piece welded steel and aluminum wheels used in farm, construction, and lower speed off road wheel. I was a manufacturing engineer for a wheel manufacturer at the beginning of my career and made many blank and forming dies to do this. I don't think you have enough press force available to get the job done with the material cold and your home made die, particularly the top will probably deflect enough that it will want to grab the part and cause problems. You could try heating the part to get this done this way.

Assuming this is a one off part, a bead roller could do the job nicely or you could clamp the top between a top and bottom support disc then work it done with a hammer to get the 90 degree flange you want, then work the waves of the flange out with a dolly.

Anything is possible.

 

[OccupantRJ]

Hammer forming. Start with a steel hammer and about halfway through switch to a dead blow, wood, or leather mallet. This will allow the metal to shrink into itself instead of stretch.

 

[cvairwerks]

Rough numbers to press form this flange in 16 ga. material is around 75 tons....

 

[tc-cad]

I do Deep Draw Sheet metal FEA using DYNAFORM Software. You never stated the draw depth of your part you want or what it is for. I may be able to help if given more information.

 

[tc-cad]

Oh I get it you are forming a flange around the circumference.

 

[rsanter]

You need to decide on the material thickness.
18-20ga and you should be able to. Use MDF and do a hammer form and make it come out fairly well.
You can also use a tipping wheel on a bead roller and then a shrinker to reduce the wrinkles

16 ga and I think you are going to have to use a steel disc for the hammer form and will likly have to use some localized heat to get that metal so shrink up on itself

You could also use a powermax hammer/machine with the right forming dies

 

[rsanter]

What are you making? It may help us understand what you really need

 

[Whiskeymike]

I have to make about a 100 of them. I have a bead roller. But they taco a little bit, and I need to use the shrinker. So it’s a bit labor intensive. I may add power to the roller to make it faster.

I do 2.5” dimple dies all the time in much thicker plate and I was hoping this was the inverse of that. (I recognize 2.5” is a lot smaller than 16” circumference

 

[dontlifttoshift]

What are you making?

Deep dish pizza pans are like nine bucks.

 

[EdT]

Hammer form would be my choice for a few parts. Big difference in difficulty between 45* and 90*. With a 16" disc and a .5" flange you have to "use up" about 3" of extra material at the edge to get to 90* and proportionately more for a wider flange and proportionately less for the shallower angle. I'd be visiting a commercial kitchenware place and find a big pan to cut down.

 

[Whiskeymike]

What are you making? It may help us understand what you really need

It’s a small run prototype for an Offroad spare tire mount for hanging bags and stuff. It basically gets sandwiched in between a 3 lug spare tire mount and the spare tire. It then has straps. I’m cnc cutting the disc, holes and strap mounts.

If there was a ready made steel flange about a 3/4-inch that I could weld on, I’d consider that. Currently browsing duct joinery parts.

I could also roll a ring, but don’t like the fit/finish of welding that on.

 

[rsanter]

Have the ring plasma or laser cut and weld to the plate
Or
Cut the rounds and have someone with a powermax put the flange on it.

If you need 100 of them I think you need to look at spinning them. Research it.
Get a large metal lathe and convert it to a spinning lathe.
Make the spin forms out of hard wood

Either way you need to finalize the design before you take the next step.
A .75 flange is harder to do than a .5 flange. Do you need a .75?
A 90 degree is harder to do than a 45 degree. Do you need a 90?
What thickness does the design really require?

Answering these questions will make a great difference in how hard and how expensive the prototypes will be.
It will also make a difference in how how expensive the final product will be.

 

[Whiskeymike]

.5 is probably enough. Maybe 60 degrees. I’ll have to tinker with it and make a few more.

Sounds like it would be a good excuse to buy a lathe.

 

[bullnerd]

Like this, but inside the spare tire? Sounds cool.

These are 1/8", pretty nicely made.

https://www.ragofabrication.com/collections/molle

Good luck, keep us posted, I'd like to see the finished product.

 

[tc-cad]

Can there be holes on the inside? You need to hold pressure ring to punch so it does not wrinkle.

 

[tc-cad]

Looks like you will need 15 tons of force on the punch to form this perimeter at 90 degrees.

 

[Whiskeymike]

Can there be holes on the inside? You need to hold pressure ring to punch so it does not wrinkle.

Yes, there will be 3 or 5 stud holes to mount on the spare rack, so I would likely make that as part of the die for alignment and clamping.

I have the CNC plasma table, so I can cut relief slots for the bend, but not sure if that would encourage tearing as it's pressed.

I need to make a few up and try a few techniques. I'll post results as I gain them.

 

[OldNeons]

I'd recommend spinning also. If you call around to different spinners you may luck into one with tooling that could make your part, or some will make inexpensive wood tooling for a small run. I've had similar parts spun in 16 and 18 gauge and they come out very nice. We used to just shear a strip and tig weld it, but that is a LOT of time welding and then finishing....

 

[tc-cad]

Pink is the Punch. Gray is the Pressure ring must be bolted through the blank into the punch (to prevent wrinkles) then push Punch through the Green Die. Simulation shows it should take 15 tons of force to force punch through the Die.

 

[tc-cad]

That is a Section View of the Die Design.

 

[cvairwerks]

Looks like you will need 15 tons of force on the punch to form this perimeter at 90 degrees.

Sounds low for forming a flange on a 16 inch diameter blank of 16 ga steel.

 

[matt_i]

The bigger issue imo is keeping the punch and die aligned and parallel to each other. It needs a beefy guideway to keep a 16" diameter punch & die aligned, no way the bottle jack can handle the side load.