Dimple dies

Fishnbeer · Aug 28, 2020

I am looking to dimple some 1/8" plate for a project. I would like to be able to do up to 3/16. I have access to a 25 ton press, I figure that should handle 1/8 fine but dont know how much pressure you need for anything thicker

Any tips on dimple placement? Staggering hole sizes... is that just for aesthetics? How far away from an edge can/should you put a dimple?

I saw ruffstuff has a set with sizes I would likely use, some other ones on eastwood say they only handle 1/8". What other brands should I look at? What are the downsides of a "cheap" set?

snivilous · Aug 30, 2020

I got the TMR 5 pack that go from like 1/4" up to 3" or whatever, no complaints at all, also never tried anyone elses though. I have a 20 ton HF press, and it'll dimple up to 1/4" fine, though the dimples don't have much deflection relative to that thickness so it bounces back quite a bit compared to 1/8" or 3/16", but it'll push it flat no issue.

Dimples seem to be pretty aesthetic, someone had a good way of putting it as "you can lose material without losing stiffness". A dimple in a plate will increase the stiffness of any fold lines trying to go through the dimple, but then it'll just move to the next weakest area which would be next to the dimple. Likewise, you could have a bunch of dimples in a circle or line, but if you tried to fold the sheet on a line that in any direction didn't pass through the dimple it would still be flimsy in that direction. So the point is, a dimple locally makes the part stiffer but not really globally for all purposes--thus the saying that you can remove material, and not make the part weaker since you made it stiffer where you removed it so the lack of material and increased height/stiffness cancel out.

As for placement away from things, on my dimples there's a very clear circle of the outer bend of the dimple. Usually it's like a 1" dimple has a 1.5" bend diameter or something. For most cases as long as your dimples don't overlap that outer diameter (which is where the bend actually starts) then you're fine. As far as edge placement, the same kind of applies but I usually add some filler. imo you want a little, even if it's 1/4", of flat surface from the edge until the bend starts. Which on that note, 1/8" will warp like a mother fucker. Even though the outside of the dimple will be flat, the flat area will get sucked up a bit I guess you could say and deform the plate. With 1/8" it's not a huge deal since you can easily bend it flat again, but I'd be aware of it. You could do a bunch of dimples and it comes out as a potato chip. One trick that can help is using the female dimple against just a flat plate to help flatten the works out a bit.

Also, more food for thought: my dimples are standard sizes, like 1" and stuff. On the plasma table I usually go .030" over and the dimple will fit in snug. You don't want to go too loose, because as it dimples the bore will open up a bit. It's better to be tight and have the press force the dimple through than be too loose in my experience. If you don't have a plasma table, there's things called plasma stencils (I have a set from 911 motorsports) that are just cut outs setup for your torch shroud to use as a template, and makes cutting holes super easy and fast.

jamscal · Aug 31, 2020

I have the eastwood set...seems like the best bang for the buck. Never tried 3/16 though.

Fishnbeer · Sep 4, 2020

Ruff stuff has a set of 1/2 3/4 and 1" on sale for $70 so I got em. Drilled a couple holes in some scrap 1/8 and put it in the squisher. Came out good but the plate warped quite a bit...looking at it from the sides there is a tiny gap between edge of die and the material, as if a little more pressure would have flattened it out all the way.... turns out the press is a 17 1/2 ton, not a 25 ton like I thought.

I pressed one more dimple on some thinner material and worked out real nice, but I really want this 1/8" to go flat...

Fishnbeer · Sep 4, 2020

Went back over it with the bottom sitting on the arbor plates and just the female die on top. It squeezed it flat which is good but in the process also left a ring around the dimple... meh. Good 'nuff

Fishnbeer · Sep 4, 2020

Aluminum chain guard for a buddys go kart. Better watch out, everything in the house is gettin dimpled this weekend!

Fishnbeer · Sep 5, 2020

I was up late last night and I kept looking for material to put some dimples in. Grabbed the dog bowl and put a few dimples in it. Looks really good but does not hold food or water anymore

j/k what i did find in my tinkering is the quality of the hole is very important, which is kind of stating the obvious, but some quick prep and clean up makes a huge difference. The first holes I didnt clean up at all and ended up with jagged edges. The next ones I hit with a roloc disc after drilling and looked pretty good. Then I put a light chamfer on each side using a step drill bit and it came out perfect.

I think using plasma stencils as mentioned earlier would be a better option for larger size holes, and follow up with a grinding stone. Maybe a knockout die would be even better, but I have never used one so this is purely speculation. Right now I only have 1" and smaller does so regular old drill bits are working just fine

RobC · Sep 6, 2020

I used sockets from my 3/4” drive set and some big bolts and flat washers and dimpled some 22g sheet metal before. It was pretty fucking mint.

JamieRC · Sep 6, 2020

Tmr ones work nice

94toytruck · Sep 6, 2020

I have a old set of hellfire ones and they've been fine.

GLTHFJ60 · Sep 9, 2020

Fishnbeer said:
I was up late last night and I kept looking for material to put some dimples in. Grabbed the dog bowl and put a few dimples in it. Looks really good but does not hold food or water anymore

LOL, that's fuckin funny.

Has anyone made dies from scratch? I've got a lathe, some round stock, and an itch to use it. What kind of angle do you build into the die? I guess I'm looking for a cross-sectional diagram, to see what the major and minor diameters are of the taper in each the top and bottom dies. That's the only tricky part I can think of, getting that right so it doesn't pinch the material before flattening out.

Fishnbeer · Sep 9, 2020

I was kicking around with the idea of turning some on a lathe too. It is some kind of steel alloy, not sure what so I am not sure if regular HSS cutters would work. The tapered part of the die looks like its a straight 45* cut, not contoured or anything. Now the dies have some clearance in between them. I put some grease in there and put them together and its like an 1/8" gap between the dies on the tapered section. On the shank that goes through the hole there is also some clearance between the 2 dies, probably so they wont bind while pressing them.

arse_sidewards · Sep 10, 2020

Fishnbeer said:
I was kicking around with the idea of turning some on a lathe too. It is some kind of steel alloy, not sure what so I am not sure if regular HSS cutters would work. The tapered part of the die looks like its a straight 45* cut, not contoured or anything. Now the dies have some clearance in between them. I put some grease in there and put them together and its like an 1/8" gap between the dies on the tapered section. On the shank that goes through the hole there is also some clearance between the 2 dies, probably so they wont bind while pressing them.

Unless you intend to use the die in a press that's part of an actual production line and is cycling thousands of times per day dies made out of axle shafts and side gears you took out of the scrap pile should outlive you.

GLTHFJ60 · Sep 10, 2020

I was thinking just regular cold rolled steel, turned down and maybe heat treated with a torch and some used motor oil. Like arse_sidewards said, it's just for intermittent use, so I wouldn't expect them to wear out in my lifetime.

Thanks for the tips Fishnbeer , that should be enough info to rough out some test pieces. What diameter hole to start with though...

YROC FAB · Sep 21, 2020

I have a home built set made out of cold rolled steel my buddie made me over 10 years ago while he was in a cnc machine shop college class. i have done hundreds on most if not thousands of dimple dies on some of them. I have dimpled 1/4 plate with them a few times but i had heat the plate up when i did it so i was a more detailed dimple.

Yes some of them will warp the panel depending on thickness but its nothing a few whacks with a dead blow wont fix.

Mine have a little more dimple on them then some of the commercially available ones at least my smaller ones do. I bought a TMR one and its virtually useless (screwdriver one). It has almost no dimple especially compared to my home made one next to it. Both are just 1/2 dimples.

billybob_81067 · Sep 21, 2020

I bought the barbed wire off road set that is sized for the HF hydraulic knockout punch set and couldn't be happier with them... I can dimple the middle of a 4x8 sheet of plate, or dimple something in place already welded to a project. The hydraulic knockout tool plus an air over hydro foot pump (also from HF) make it easy...

Muckin_Slusher · Nov 22, 2023

I'd like to buy a set, they're all on sale now or soon.

YROC FAB I'd like to buy the swag set I think, but the TMR ones are much less expensive since I'm in Canada. Your comment about them not having enough flare bothers me though. Do you know how the TMR compare to Swag or others?

You said your homemade sets have way more flare than commercially available ones do. Why is that? Is that a good thing? Any issues with the edges of the holes cracking? Do they look better and/or add more stiffness?

Edit: More questions.

What dies can be used with hydraulic draw studs (like greenlee knockouts)? Obviously the smaller ones don't have big enough through holes to fit the draw stud, can these ones be used with manual draw studs (bolt with thrust bearing) be used?

TMR 1/2 inch only has a 1/4 inch through hole, haven't looked to see how much force it takes to punch 1/8 vs how much tension a 1/4 inch fine thread bolt will suffer.

buzzbombxj · Nov 22, 2023

I regret not buying a set with a through hole, it would open up so many possibilities.

Muckin_Slusher · Nov 22, 2023

In Canada, there's also this option.
It's cheaper and has more sizes, including 3 inch, but solid with no through hole.

I've no idea what brand or who makes them. Apparently "heat treated" steel, so similar to TMR?
Also have no idea what a DZUS is.

10pc Dimple Die Set

Dimple Dies are used to flare or flange existing holes to strengthen sheet metal. Made of 8620 Heat Treated steel, these dimple dies are sturdy enough to stand up to constant heavy duty use.Set Includes the following size Dimple Dies:(1) DZUS(1) 1/2"(1) 3

www.kmstools.com

Brad · Nov 22, 2023

Muckin_Slusher said:
In Canada, there's also this option.
It's cheaper and has more sizes, including 3 inch, but solid with no through hole.

I've no idea what brand or who makes them. Apparently "heat treated" steel, so similar to TMR?
Also have no idea what a DZUS is.

10pc Dimple Die Set

Dimple Dies are used to flare or flange existing holes to strengthen sheet metal. Made of 8620 Heat Treated steel, these dimple dies are sturdy enough to stand up to constant heavy duty use.Set Includes the following size Dimple Dies:(1) DZUS(1) 1/2"(1) 3

www.kmstools.com

Dzus is a 1/4 turn fastener with a bar/spring used mostly in sheet metal panels. Maybe it has a wider or shallower flare

YROC FAB · Dec 3, 2023

Muckin_Slusher said:
I'd like to buy a set, they're all on sale now or soon.

YROC FAB I'd like to buy the swag set I think, but the TMR ones are much less expensive since I'm in Canada. Your comment about them not having enough flare bothers me though. Do you know how the TMR compare to Swag or others? No

You said your homemade sets have way more flare than commercially available ones do. Why is that? My colleged aged buddie made them with zero reference to what would or wouldnt work lol. Is that a good thing? Any issues with the edges of the holes cracking? Do they look better and/or add more stiffness? They look better imo. Never had any cracking. it should make it more stiffer being dimpled more. That tmr 1/2 is totaly useless is my only experience with any kind of aftermaket dimple brand.

Edit: More questions.

What dies can be used with hydraulic draw studs (like greenlee knockouts)? Obviously the smaller ones don't have big enough through holes to fit the draw stud, can these ones be used with manual draw studs (bolt with thrust bearing) be used?

TMR 1/2 inch only has a 1/4 inch through hole, haven't looked to see how much force it takes to punch 1/8 vs how much tension a 1/4 inch fine thread bolt will suffer.

CarterKraft · Dec 4, 2023

GLTHFJ60 said:
LOL, that's fuckin funny.

Has anyone made dies from scratch? I've got a lathe, some round stock, and an itch to use it. What kind of angle do you build into the die? I guess I'm looking for a cross-sectional diagram, to see what the major and minor diameters are of the taper in each the top and bottom dies. That's the only tricky part I can think of, getting that right so it doesn't pinch the material before flattening out.

From my notes...

Dimple Die
As I'm re-reading all this, I feel like a real ass. I screwed up my trig...it should have been
OD female = OD male + 2*mat'l thickness*tan(flare angle) NOT divided by the tangent...
Which makes the correct OD on a 2" OD die for 0.188" mat'l 2.264" for a 35 degree flare, not over 2-1/2" like my original post, which is WAY too much, just like you saw.
When I did mine, I just offset the surface in CAD by my material thickness to get the profile for my female die, then just dimensioned in CAD.
I'm really sorry about that...typical engineer, right? I'm glad you didn't scrap a hunk of steel, or I would have been asking for your PayPal account to send some funds...
My dies mate like your pic B.

Ghetto Fab. · Dec 5, 2023

I made my own dimple dies for my rock rails/side steps on my dodge. We didn't have a 1/2" dimple at work and I didn't want to use anything bigger, so I just made my own out of mild steel round stock. No heat treat or anything. Worked fine for 20ish or so dimples. Got the idea for the dimples from the back of a firetruck. Had the step laser cut out of 1/8" then I formed and dimpled it. In retrospect, I should have just put holes in the steel, then used a stainless steel overlay that had the dimples in that as the powdercoat has worn off the tops the dimples now. Oh well.