The short version of the story is that I'm trying to bend some 1" diameter by .083 wall steel tubing. This is for a school project and things just aren't bending correctly. All of the bends are kinking, except for the black pipe that we tried. The rules call for 1018 or better steel, and the black gas pipe really is too heavy.

Can anyone make a suggestion about getting a better bender or tubing to bend? We are currently using a swap meet special bender, the type with the bottle jack and adjustable rollers. We obviously don't have much money to spend so one of the nicer benders is out of the question. I would go to an exhaust shop, but they don't have the right tooling to bend 1".

 

How many degrees are you trying to bend it? Heating up the pipe and bending it slowly might help.

 

We didn't think about heating it any, are you suggesting that we should get it red hot? The critical bend is just a hair under 90* and another is about 45*.

 

Have you tried packing the tube with sand, and then using the hydraulic bender?

Not sure if this is an urban myth or not, but I've heard you shouldn't fill a tube with sand and then heat it with a torch, supposedly the sand "melts" and turns into glass?? Beats me if it's true, but you might not want to take the chance

 

i would try keeping it hot and slowly bending it too.... if that doesnt work, try to find a fab/chassis shop that has a bender ment for that tubing and see if they will help you out......

 

It seems that you found out the hard way the difference between a tubing bender and a pipe bender. You need a bender that draws the pipe around a mandrel, not one that simply pushes down on it between two points. You may want to try an electrical conduit bender (or "hickey"). It'll probably work on the diameter/wall thickness you're using, if it is a strong one (Ridgid, Greenlee). They're relatively inexpensive, or they can be rented also. Keep in mind that they are sized by internal diameter, so you would need a 3/4" size bender.

 

Thanks for the idea Mike, I know there is a local place that rents tools and stuff. I'll see what they have to say about it.

 

Someone above got close.

Your problem is that you're using a pipe bender to bend tubing. To be more specific, "pipe" does not come in even diameters. For example, 3/4" sch. 40 pipe has a 1.05" o.d. If you use those dies to bend a 1" o.d. tube, it will "squash" at the bend.

You need a 1" die to bend 1" o.d. tube, and you'll be good to go. Or, you need to use pipe instead of tubing. That's why the "black pipe" you bent came out good, it was the correct size for the dies.

Steve

 

i used a big conduit bender to make my kart frames, also pipe sizes and i use bending steel tubing not pipe. for my nurf bars i had some really shapr bends and i filled the tube with abrassive shot and duct taped the ends ,it worked out pretty good but not perfect

 

this is for steve

do you think the cheap ($100) harbor freight bender will do good with mild steel tubing up to say 1 1/2". it is nothing more than a jack and some die's. I would love to get on eof those powered benders that draw the tubing around but for hobbie stuff thats a bit steep.

 

damn shame you never ask me i have one of the cheap benders from harbor freight

 

Actually, while plumber's pipe and electrical conduit tubing (EMT) are both measured by their ID, their OD are not the same due to different wall thickness. 3/4" EMT conduit has an OD of .922" (thinner material than pipe), therefore regular 1" OD steel tubing will actually fit rather tightly (if at all) within a 3/4" conduit bender. My suggestion would be to bring a small length of your 1" steel tubing to your local home improvement store (or renter center) and physically see how it fits in different 3/4" hickeys, before buying (or renting) it.

In all actuality, all the steel tubing that I've bent for various projects (above 1/2" OD and not household electrical), I use a mechanical bender from Pro Tools with the appropriate dies, that makes absolutely beautiful bends. I just mentioned the EMT conduit bender idea to help someone with an inexpensive alternative that just might work on 1" x .083" steel tubing.

 

This one is for EDE

do you think the cheap ($100) harbor freight bender will do good with mild steel tubing up to say 1 1/2". it is nothing more than a jack and some die's. I would love to get on eof those powered benders that draw the tubing around but for hobbie stuff thats a bit steep.

 

The $100 Harbor Freight is the same idea as what I have now. The only stuff I got to bend nicely is the black pipe, even some of the smaller conduit tubing kinked on us.

 

Another thing to consider is with 1" rigid pipe you're not gonna be able to bend a 90 with a hand bender. Hickiey's are a shorter radius bend than the EMT benders which adds to the problem. The 45....maybe, but It'll probably look like crap. Hickey's are good for tweaking a pipe if necessary for things such as small kicks or trying to get a "dog-leg" out of a pipe. Whatever you do....don't borrow somebody's EMT bender to try and bend your pipe, because all you'll accomplish is making their bender unaccurate. As an Electician I can vouch for that.

 

No, the Harbor Freight bender is for bending "pipe", not tubing. The dies that come with are for schedule pipe sizes, not tubing sizes.

Now, if you're gonna bend "pipe", then yes, they work fine.

Steve

 

crap

 

we've been bending pipe and tubing here for 30 years, i can tell you that tubing is much easier to bend than pipe, unless it is schd 40 pipe, 20 (the cheap crap) kinks very easily......

if your using a 1" OD tubing, then like people have said, the correct dies will help you out, but the length of the radius is just as important as the angle......

if you try to make the bend over too short a radius the pipe will kink and break

we have a large bender here that can handle up to 4" tubing, but it would be difficult to bend 1" in it even with the right dies just because its so large, so there is alot to be said for having the right bender as well.

as far as size goes, it also depends who your talking to.....if your talking to us fence guys, its 1 - 3/8", 1- 5/8", 2", etc...... because we are concerned with OD

but if your talking to plumbers its like 1- 1/4", etc cause they are talking ID....we run into this problem with one of our vendors all the time when trying to order speed rail fittings to fit our 2" pipe....(its a plumbing supplier)