Bending a radius on flat stock

[Pat]

Hi,

Anyone out there that does, or knows how to produce a radius on flat steel stock. Because of my severe lack of understanding of the technical names for a procedure like this, I will try to explain it the best I can. Lets say you have a 6 foot long piece of 2" x 1/4" mild steel flat stock, and your goal is to have this piece of flat stock lay flat on top of a railing that has a slight radius to it. What type of equipment is needed to bend the radius, and any suggestions on different equipment brands. I have seen this type of bend but have know idea of what is involved in creating it.............thanks

[neimad]

I take it that the stair is of a spiral type and the rail needs to spiral, not become a ring?

I may be asking the obvious, but wanted to clarify

[Pat]

neimad,

No spiral to it. I guess to better explain it, if that same 6' piece of 2"x1/4" flat stock was placed on a table lying flat, bring both ends while still lying flat towards each other creating a radius on the edges...............thanks

[enlpck]

Lots of options, a few of which are

Bend between pins (bump bend) with plates clamped loosely sandwiching the assy to keep material flat. Work slowly. You can always bend a little more where the radius isn't right. Drawback: If you don't use a lot of care, radius won't be uniform, and the pins tend to dimple the edges, requiring finishin after bending.

heat a section at a time and bend. Put bar on EDGE, over the end of a table, or better , a form of the correct radius. If the radius isn't too tight, just the heat may do it. Heat the lower edge and let gravity do the work. As the metal cools, it will pull in the radius. This can be very smooth , but takes practice.

Buy, rent, borrow, build, or contract for a roller setup with guides and followers for bending the hard way. As long as the bend isn't too sharp, excellent results can be had.

get piece of bar or plate the same thickness and wide enough to set the curve on, and cut away everything that isn't your curve. Time consuming w/o CNC, but excellent results and easy.

There are many more.

[Pat]

enlpck,

Thank you very much for the bending information. I think I will practice with the heat method to see what I can do.............thanks again.

[SDean]

Pat. I think the term you are looking for is to have it rolled the "hardway".

How long of a piece? And how much radius are you looking for?

You might check with one of your larger fabricators that does tube bending and have them do it. (I am waiting for some Channel to be rolled the hardway and some Rect Tube rolled the easy way. It's not cheap!)

Since you're setting up your shop, maybe it's time to add a Heller Universal Ring Roller to the list. :-)

Link to Heller (http://www.hellerson.com/urrca2000e.htm)

[Pat]

SDean,

Thank you for the correct terminology. As far as how long of piece I need and how much radius, I don't have an actual need at the moment. A friend asked if I had the ability and desire to make some half oval balcony railings from blueprints. Told him the desire to work with metal is always there, but the ability issue is questionable. Thanks for the Heller machine link. I noticed that they don't quote the prices of them very handy looking tools. I am afraid to request a quote. Maybe someday when I can justify the expense and have the money, I will have one of them fine units. But for now I am semi-broke from pursuing my mad dream of a mobile weld/fab business.............thanks again

[SDean]

I think you can get the 2000E for just under $5000. :cool2:

[wolfgangwelding]

If i were you I would cut the metal to length you want. Take it to a local fab shop have the flat stock rolled to the correct arc and add the cost of that to your labor. I guess I should have asked if your friend was a paying friend.

Rolling this metal is a special service that takes special machines to do it fast and people charge for that, even if you don't have the rollers your self you cutting the metal and having the metal rolled is a service and you should get the money to pay for the rolling and then some for your labor of getting it done.

[SDean]

takes special machines to do it fast and people charge for that.
And boy do they charge. I am waiting for 3 pieces of 4" x 5.4# channel rolled the hardway (207" radius) and 2 pieces of 1 x 3 x .120 rect tube rolled the easy way (252" radius). I finally found a shop that would do it for $395.00 (the other quotes were $500) plus material.

I shouldn't have passed up the opportunity to buy that Heller Ring Roller at that auction a couple of years ago.:(

[Ries]

It seems like everybody always wants to put a quart of beer in a one pint glass- some things there just aint cheap, easy, and quick- pick one- two if you are really lucky. But all three- fugedaboutit.
Actually, blacksmiths bend flat bar the hard way by hand, usually over the horn of the anvil, but it takes a good eye, a strong arm, and a lot of heats.
The next step up is a real hossfeld bender- not some chinese copy. My hossfeld will bend flat bar the hard way up to at least 3/8" x 3" or so. Much bigger, and I do it hot on the hossfeld. Of course, a real hossfeld costs about 600 bucks for the basic setup, and then to get repeatable curves, you need the dies to bend angle iron flange out. Figure at least another 800 or so for the base die, plus a few fixed radius dies. More if you want the whole set- from 3" radius up to 36" radius. But that hossfeld setup will bend accurate repeatable circles or curves in angle, solid square and round, flat bar the hard way or the easy way, square tubing, and lots more.
Next step up is a real section roll, or angle roll. Buffalo used to make these back in the stone age, now most of the ones you see are imports. I am partial to my italian built Curvatricci, sold by eagle bending-www.eaglebendingmachines.com/
They actually have a machine for around 3500 or so, up to a hundred grand if you need to roll those 18" I beams. It wont do as much as a hossfeld, but what it does do, it does quick and easy.
But to move metal easily just how you want it, you gotta either spend real money, or lots of time to copy a real machine.

[Pat]

Ries,

Thank you for the information. Trying to get by the cheapest way possible is not my intent, but I don't think there is anything wrong with the less expensive alternatives if you have the time and ability to slap together something that will satisfy your requirements and do it safely. I am very interested in the hossfeld bender you mention. I bought a Harbor Freight bender (live and learn) that turned out to be the most inaccurate cheaply made piece of crap (my opinion only) that I have ever purchased. A few moths back I tossed it all in the scrap bin and have since given the floor mount pedestal to a neighbor to use as a stand for his bench grinder, and other parts of it have found their way into other projects. Using the hossfeld to bend the hardway, do you use a torch to heat the metal, or some other method? I would be very interested in learning how this is accomplished.........thanks

[enlpck]

If I remember, I'll take some shots of the hard-way setup up our bender later today, and some of the work done on it. The mandrels and followers arn't hard to make. A lathe makes it easier, but isn't absolutely needed, if you are willing to weld rounds together.

[enlpck]

A few shots to show the general idea. The bender isn't set up for a follow bend right now, but these are the parts.

First, the bender: 36" table, 12+ inches inside the harp, 1 1/2" dia center pin, 1 1/8" dia pins on the harps

[enlpck]

The follower for bending 3/8 the hard way. The step is 3/8 to match the material thickness, and the depth is about 1 1/4". Its good for up to about 2 1/2 wide material, though at that point, it literally requires 4 men and a boy to pull the bend by hand, using a 6 foot extention on the follower harp. Bends on this material are done cold.

[enlpck]

The washer on top of the follower is for shiimming the follower snug. The follower goes on the harp that is pulled. The radius mandrel goes on the large center pin. The follower is heavy wall pipe, about 4" dia, with end caps welded on. The radius mandrels are a variey of solid (for the small ones) and hollow. We made the follower for a job, the radius mandrels came with the bender. Some of the mandrels (up to 30" dia) are shown.

[enlpck]

The centers are heavy, up to well over 100 lbs. Setup can be.... fun..... but the result is worth it. Here is a ladder with two perfect hard ways, 3/8X2 hot roll, 7" radius at the centerline, bend cold. Got both the first time.

[enlpck]

(the ladder goes on the locomotive tender next to it, and is will be shot when the next coat of paint is shot. Black Centari)

This (last) shot is a bend in 3/4 by 8" hot roll. It is a tight bend and required heating. A template was used, and we bent, release to check, and tweaked. Several parts were made, and by the time we were done, the center pin needed straightening and the heat treat needed to be redone.

[Franz]

And just how many beers were put in those 4 good men after bending that ladder to reenable them hydraulicly?
Pictures like that make me remember exactly why I wasn't interested in the free barge chanel bender. Hell, I wasn't even interested in takin it out of the floor for pay.

[enlpck]

Not enough beer. Fortunately, bends this heavy arn't real common for us without mechanical aid-- Does a '68 Euc with ballasting a 20 ton come-along count as hydraulic?

[Ries]

Actually hossfeld makes dies that will bend that flat bar the hard way quite easily- one guy, no beer, 5 minutes. I bend stuff the hard way all the time with my hossfeld.
The chinese benders are actually knockoffs of the shop outfitters bender. The shop outfitters bender is an attempt to sell a hossfeld bender for half the price.
The real thing is so much better there is no comparison.
Now that the patents have expired, there are at least 3 companies making hossfeld compatible benders-
Hossfeld itself, which has been in business for at least 50 years, and has the tooling to produce a huge array of special purpose dies. In 1989 I toured the factory, and every wall was hung with wooden patterns to make cast iron dies. They are the most expensive, but they have every die you can think of.
www.hossfeldbender.com/
American Bender- they make their benders on a cnc mill, and have them heat treated- they are cheaper, but very high quality. Totally compatible with hossfeld. They only make a limited range of dies, however, not including the edgebending the hardway dies. $775 for bender with basic tooling. They are working on a cheaper model as well.
www.americanbender.com/
JD squared- these guys are more automotive oriented- they specialise in tube dies for things like roll cages. They have a nifty hydraulic assist, much better than the hossfeld power version. Again, a limited supply of dies.
www.jd2.com/

These are real tools that will last a lifetime- and they are priced accordingly. But I have had my hossfeld no. 2 since about 1978, and I have bent hundreds of thousands of bends on it. It is repeatable, accurate, and will bend almost anything- this week we will be bending 65 pieces of 3/4" square bronze to a 36" radius, 130 pieces of 3/8" stainless to a precise "s" shape, several hundred small pieces of round bar to a 72 degree angle, plus a lot of tweaking things straight, right angles for brackets, and who knows what else. This is a typical work week for the hossfeld in my 4 man shop. I used it to bend 1" x 4" into a driveline loop for my tractor, 1 1/2" square tubing into 20 foot radius arches for my carport, 1 1/2" schedule 40 pipe for handrails, straightening stainless steel pipe after it has been forged, making scrolls, bending round bar, square bar, flat bar, pipe, tubing, angle, you name it.
Plus, it is made in america.
If you bend anything, with any bender, I would advise buying the hossfeld instruction manual. It costs around 15 bucks, and it shows their die setups to bend just about anything. Many of the dies could be shop built, if only you knew what to build. Their book shows die setups that work. If you are gonna copy something, copy something that works.

[smithy]

build hot fire Lay out arc of radius on concrete floor heat metal
use concrete floor as anvil if you cant find one
don't hit cold metal as it hurts the dumb hand
don't forget to squint or if you prefer wear safety glasses

because as they say
you can walk on a wooden leg
you can eat with false teeth
but you cant see with a glass eye