Bending the Spine of Angle Iron

I would like to be able to bend 4" long 1.5"x0.125" A36 Angle back along its "spine" (for a lack of technical term) for an offset of 1/2". Require at least 0.75" flat (unbent) from each end. So the spine profile would sort of look like;



Going to make 200 pieces for a first run and this would be re-occurring several times a year.
Any suggestions on how to bend this?

How close to 90 degrees does the angle have to stay?
Can you machine a form of the right shape?

Chip

Farm it to a shop that can bend,easy peasy,no?
Gw

In order to bend angle iron and keep it flat and square you must first bend the opposite side at 3 times the radius of your target radius and then bend it the way you want the final bend. This is very difficult to describe without appropriate drawings to demonstrate the process. Once you see it done it makes sense.
If you can find the book "Recipes In Iron" by Francis Whitaker, there is a section on bending angle iron.

Bob
WB8NQW

Taking Chip's suggestion, I'd look at using a shop press with a set of formed dies for that many pieces.

Chris

I have a Marchant kick shrinker/stretcher setup that would make easy work out of it.

I wouldnt buy a set just for this job, though. You asked how it could be done, though

A hossfeld will do it.
Hossfeld Bender Catalogs | Hossfeld Dies and Parts | QuickStart™ Toolsets | Hossfeld Universal Bender
page 37 on the universal catalog 100 here.

this is a standard die for a hossfeld- its a 42980 angle iron heel outward die. they are sold in two sided dies, each one has 2 fixed radiuses.

You would need to buy a basic hossfeld, around $650, and then these dies- probably get the whole shebang, new, from Hossfeld, for around a grand.

Call em and ask.

Yep, its an armstrong tool (you use your own muscle to bend it) but the mechanical leverage advantage is enough that its no big deal. You could knock these out in a couple of hours.

This would be the cheapest, fastest way to do it- no machining, no custom dies, no wondering if it will work after you spend two days making tooling.
Hossfelds work.
They figgered it out fifty or sixty years ago.

Lots of people who have never done this will offer suggestions they think might work, if you build custom tooling.
They have never used a hossfeld.

(Francis Whittaker was a cute ol' curmudgeon, but he wasnt any kind of fabricator, and he pretty much never made more than one of anything in his life. He had no clue about any 20th century metalworking techniques. He was a great introduction for teenagers into blacksmithing, but his technique will take you an hour each piece. He got paid to teach, not make parts)

Ries said:

A hossfeld will do it.
...this is a standard die for a hossfeld- its a 42980 angle iron heel outward die. they are sold in two sided dies, each one has 2 fixed radiuses.
Lots of people who have never done this will offer suggestions they think might work, if you build custom tooling.
They have never used a hossfeld.

Click to expand...

What he said. Hossfeld RULES.

Might need to xplane how your going to get the two flats and the tight radi with some of the shelf dies.

Ries said:

A hossfeld will do it.
Hossfeld Bender Catalogs | Hossfeld Dies and Parts | QuickStart™ Toolsets | Hossfeld Universal Bender
page 37 on the universal catalog 100 here.

this is a standard die for a hossfeld- its a 42980 angle iron heel outward die. they are sold in two sided dies, each one has 2 fixed radiuses.

You would need to buy a basic hossfeld, around $650, and then these dies- probably get the whole shebang, new, from Hossfeld, for around a grand.

Call em and ask.

Yep, its an armstrong tool (you use your own muscle to bend it) but the mechanical leverage advantage is enough that its no big deal. You could knock these out in a couple of hours.

This would be the cheapest, fastest way to do it- no machining, no custom dies, no wondering if it will work after you spend two days making tooling.
Hossfelds work.
They figgered it out fifty or sixty years ago.

Lots of people who have never done this will offer suggestions they think might work, if you build custom tooling.
They have never used a hossfeld.

(Francis Whittaker was a cute ol' curmudgeon, but he wasnt any kind of fabricator, and he pretty much never made more than one of anything in his life. He had no clue about any 20th century metalworking techniques. He was a great introduction for teenagers into blacksmithing, but his technique will take you an hour each piece. He got paid to teach, not make parts)

Click to expand...

Heavey Metal said:

Might need to xplane how your going to get the two flats and the tight radi with some of the shelf dies.

Click to expand...

I am guessing you have never used a hossfeld, then?

Because, with the fixed radius dies like these, it naturally gives you two flats, assuming you center the piece in the die, and pull. You may, depending on the length of the desired piece, have to cut the ends off the factory die, but thats no biggie, its cast iron, and cuts pretty easily.
The radius dies vary in length, depending on the radius and application, but none of them are longer than about 8", and most are more like 4" or 5".
The one I linked to, if you had taken the time to read it, is about 6" long, maximum. A bit of work in the bandsaw, or even with a 4 1/2" grinder and an .040 cut disc, and it can be any size you want, over about 3".
The way you pull a longer arc, or a complete circle, is by multiple pulls.
Visualize a press brake, which has a curved upper and lower die- it only bends a curve in the section of metal that is in the die, so if you want a larger arc, you do multiple presses.
A hossfeld, in this application, is basically a horizontal press brake.

I do partial arcs with straight ends all the time on my hossfeld, in flat, round, square, hex, square tube, angle iron flange in or out, and flat bar the hard way.

Did everyone miss the fact that the pieces of angle are only 4" long. Gonna be tough to hold in a Hossfeld. For that length and that amount of bend I'd make up a simple die for a press and have at it. Don't overthink it; it's a simple job...

If I needed to do this, I would cut pieces of the angle about 3' or 4' long, and bend multiple sections, with straights in between, then cut them afterwards.
Yes, there would be some waste- a few bucks worth of material, when you discard a couple inches between each bend.

But, if I was going to make a "simple die", I would end up spending a day or so at the milling machine, cutting V grooves in a big block using my rotary table. Then cutting a reverse V, again using the rotary table, in another big block. I have found that to make a 4" die work like this in my press, I would need to start with something like a 6" x 6" x 8" piece of steel.

Now maybe I am just dumb- and there is some quick and easy way to make a die like this.

But to me, buying off the shelf dies that are proven to work, versus machining curved V grooves, and calculating what I THINK springback and groove depth should be to accomodate variations in material, and ease of die use, is a no-brainer.

I bought my hossfeld in 1978.
It has earned its keep a thousand times over, and, the great advantage with its modular tooling is that I can use the same tool for the next job, just by using different dies. No making, storing, and then forgetting the purpose of shelves full of hundreds of pounds of one time use tooling.
(not that I dont do that too)