May 01, 2005

How to Bend Tubing and Pipe by Hand

Most people seem to think that you need expensive machinery or heat to bend metal. It isn't generally true. Basic bending can be done with nothing more than ordinary shop tools, a bit of elbow grease, and some ingenuity.

Somewhere around 1978, I took a theater materials class and learned how to weld. As part of a sample prop I'd decided to build, I needed to make some 3" rings out of 3/8" steel rod. The only way I could figure out how to bend them was to weld the rod onto a piece of pipe, clamp it in a vise, and twist it around the pipe. Before I did this, my teacher walked by and told me I'd need to heat up the rod with a torch in order to bend it. "Oh yeah?" I replied, as I wrapped the rod around the pipe three times. I suppose I've felt a certain smugness about my metal mangling abilities ever since.

When I first started working in professional theater shops, the only way I saw metal tubing bent into shapes was by cutting partway through the tubing at intervals, bending it, and then welding the kerfs closed. It's a simple method that's easy for a hack like me to understand, but it's tediously slow and usually produces a weak and ugly product. And welding the kerfs closed causes a lot of warpage, so you never know exactly what you'll end up with.

Paying a vendor to do roll bending is one alternative, but it slows down the creative process, and it's not useful for artsy shapes or ellipses. Machines (unless they are very expensive) usually only bend one radius at a time. You end up having to weld a bunch of pieces together, so it's not much better that the kerf and weld method.

After years of frustration with this, I finally saw someone bend tubing with a homemade jig. It seemed magical at the time, but it took me a few more years of intermittent fiddling to understand the process well enough to be able to produce consistent results. In the years since then, I've learned a lot more through trial and error. And spilling some blood. I hope that the following ramble will help you understand the process and its pitfalls a little quicker than I did.

A Word of Warning

I mentioned blood. Metalwork is dangerous. You will hurt yourself. How bad is up to you.

Bending metal requires some strength, but mostly it requires that you figure out a way use the metal you want bend as a lever to bend itself against a form that may be destroyed in the process. When that happens, you need to be prepared for the outcome. Flesh is weaker than metal, and concrete is harder than your ass or your elbow. If you do much of this, all these things will become acquainted with each other eventually.

Consider yourself warned.

Tools and Jigs

What sort of equipment you'll need for bending depends on the size of the tubing you want to bend. For anything 1" and up, you'll definitely want a sturdy, well braced table bolted to the floor. You can get by for a while with a plywood top, but it will eventually get destroyed. My table has a 1/4" steel top, which allows for permanent holes for jigs and stops that won't tear out without serious abuse. This will work well for any bending up to about 2". For anything heavier than that you'd probably better call a professional anyway.

I've mostly always used 1/2" steel pins and bolts to locate the jigs. 5/8" would be better for heavy bending, but it isn't usually necessary. Bent pins are easy to fix or replace. A few large C-clamps will help keep the jig from slipping and tearing out the holes.

Spend some time thinking about where you're going to bolt down the table. Ideally, you'll want at least a 20' radius (from the jig) of clear space on two sides of the table, and a good 10' on the outfeed side. The best way I've found to anchor the table is 1/2" threaded rod and anchoring cement. Normal anchors, even big ones, always seem to fail after a while.

You'll also need a heavy duty stop to hold the tubing against the jig and a bunch of holes in your table for bolting it down. The stop and the jig must both be extremely square to the table or the tubing will twist. My favorite stop is made from a very heavy piece of 1-1/2" tubing with a bit of pipe welded on the end. The holes are offset so that I can swivel it to get a tighter fit against the tube.

jig_stop_tn.jpg trammel_tn.jpg

One other tool that's invaluable is a sturdy router with a large trammel. Routed jigs will bend smoother and with less kinking or twisting than a jig cut with a jigsaw. If you can't get your hands on a router, just make sure that the cut is as smooth and square as you can make it.

Your trammel can be anything you want, but basically what you need is to attach a stiff bar with holes in it to your router. It can even be as simple as a strip of plywood. Most routers have plastic plates on the bottom that can be removed. Just use those screw holes to mount the trammel. I've made trammels up to 35 feet long, but I have to admit that was pushing the envelope.

The jig material that I use the most is 3/4" medium density fiberboard, or MDF. 1" or 1-1/4" is even better, but I don't have a convenient source for it. 3/4" plywood will suffice, but you might have some trouble with kinking, as it's not quite as consistent as MDF.

3/4" MDF will make a perfect jig for 1" square tubing. For 1-1/4" or 1-1/2" square, you'll want to prop up the jig with some shims so that the jig is more or less centered on the tubing. With round tubing, centering the jig is even more important. If the tube is too heavy, or the jig too soft, round tube may destroy your jig. One way around this is to bend a thin strip of steel to protect the edge of the jig.

unbent_tn.jpg bent_tn.jpg
This is 1-1/4" MDF and 1" tube

For bending big tubing or pipe (like 2" tube or 1-1/2" pipe), you'll want to use a steel jig. The easiest way to do this is to bend two pieces of 1" tubing with a wooden jig and then weld and brace them together. This is actually better than a bent 1 x 2 because it's more consistent and the seam between the two pieces of 1 x 1 is the contact point where the 2" round hits the jig. And since the jig is 2" thick, it's the perfect size for a different sort of end stop. Just take some 1/4" x 1" strap, make a U around a piece of 2" round, and weld it to one end of the jig.

heavy_jig_tn.jpg wall_jigs_tn.jpg floor_jigs_tn.jpg
Some jigs

Small Bends

Homemade hand-bending may not be the best technique for really short radii. For example, 1" x 1" - 18 gauge steel tubing can be bent to a minimum diameter of about 30" before it starts to kink. This isn't an exact number because of the differences in temper and metal quality. And there are a couple of ways to cheat that number even lower. The easiest is to bend several times using successively smaller jigs. How far you can take this is something you'll have to find out for yourself. The other way, which only works for square tubing, involves pushing in the inside wall of the tubing. Here's a 5" radius jig I made for 1" tube that works like a conduit bender.


This does cause some distortion, but the tube retains most of its strength and it's a pretty darn fast technique. The ridge inside the jig is only 1/8" square wire, but the tube wall collapses about 3/8".

Manual Power

If you're capable of lifting 100 pounds, you shouldn't have much trouble bending tubing up to about 1-1/2" by yourself. For 2", a friend is usually necessary. Spend some time thinking about how you're going to land when something breaks. Something will break. You will end up on your ass.

The forces involved in this may not be entirely obvious at first. In addtion to the weight of the metal and the force that you're exerting, don't forget about potential energy. The metal being bent is a potentially dangerous spring that really wants to smack you in the head. If your jig gives way, metal and jig parts can come flying off the table with surprising speed.

Cheater bars can help you make difficult bends. But they also increase the danger. Landing on your ass with both a 50 pound piece of 2" pipe and a 2-1/2" cheater bar heading for your face is not where you want to be.

Some Tips

Bend with the seam toward the jig. The weld seam is a little harder than the rest of the tube, so there will be less chance of twisting or kinking if it's on the inside of the bend. And it's usually less visible there.

If your floor is too slick, you may not be able to push hard enough. A very light misting with some nasty spray adhesive will help.

Use the tools that are available. Difficult bending can aided by the proper application of a forklift. Jigs can be mounted vertically on shop pillars so you can use your body weight. It looks silly bouncing up and down, but it's effective.

It's always better to slightly overbend than underbend. It's easier to pop it back out a little than to bend it just a little farther. A stub of 2" tube welded to your table 2" off the floor gives you a convenient notch to unbend your mistakes.

Bending Data

Metal always springs back from the jig. Here are a few charts that show results I've gotten. Some of the data may not make sense, and some of it may be wrong. Metal hardness can vary, even from the same mill. Aluminum is more unpredictable than steel.

Hopefully, these numbers will give you an idea of where to start. If you have a better idea, just let me know.

Happy bending!

* All material is steel unless noted otherwise.
* Frequently, bending using progressively smaller jigs will produce slightly larger radii than if you just use the smallest jig first. It's just one of the weird things about how metal reacts to force.

1/2" - 20 ga. round tube
desired outside radius jig radius
144" 54"
120" 50"
32.5" 25.5"
30" 24"
27" 22"
21.75" 18"
21.5" 17"
19.5" 16"
12" 10"
1" - 18 ga. square tube (Central Steel)
desired outside radius jig radius
192" 108"
144" 85"
114" 75"
96" 65"
80" 60"
72" 55"
65" 50"
58" 45"
53" 41"
49" 38.5"
45" 37"
42" 35"
39" 33"
37" 31"
35" 29"
33" 27.5"
31.5" 26"
30" 25"
29" 23.5"
28" 22.5"
26.5" 21.75"
25.5" 21"
1" - 18 ga. square tube (MetalMatic)
desired outside radius jig radius
67" 50"
49" 38.5"
34" 28"
29" 25"
24.5" 21"
1" - 14 ga. square tube (Ryerson)
desired outside radius jig radius
456" 144"
300" 120"
258" 114"
240" 108"
228" 105"
216" 102"
126" 72"
108" 66"
90" 60"
72" 50"
42" 34"
39" 29"
31" 25"
17.5" 15"
11" 9.75"
1" - 14 ga. square tube (Discount)
desired outside radius jig radius
168" 96"
158" 90"
104" 66"
63" 47"
60" 45"
57" 42"
34" 26.5"
22.5" 19"
18.75" 16"
1-1/4" - 14 ga. round tube
desired outside radius jig radius
33' 12'-6"
20' 10'
16'-6" 9'
15' 8'-6"
14' 8'
13'-6" 8'
12'-6" 7'-6"
12' 7'-6"
11' 7'
10' 6'-6"
9' 6'
8' 5'-6"
7' 5'
6' 54"
5' 52"
63" 50"
54" 44"
47" 38-1/2"
44" 36"
42" 35"
37-1/2" 32"
33-1/2" 28"
30" 26"
25" 21"
1-1/2 - 18 ga. square tube
desired outside radius jig radius
180" 120"
168" 114"
141" 102"
108" 84"
84" 72" first, then 66"
1-1/2 - schedule 40 alum. pipe
desired outside radius jig radius
204" 96"
108" 68"
132" 75"
67" 48"
48" 36"
2" - 12 ga. round tube (Ryerson)
desired outside radius jig radius
228" 144"
168" 120"
156" 108"
144" 96"
84" 75"
44" 36"
28" 25"
2" - 12 ga. round tube (Discount)
desired outside radius jig radius
173" 108"
115" 96"
96" 75"
84" 68"
75" 50"
70" 50"
54" 46"
36.5" 29"
31.5" 25"

These tables are admittedly incomplete. I will update them when and if I've got more data and more time. If you come up with a reliable list of your own, feel free to send it to me.
Posted by Hal Eckhart at May 1, 2005 02:34 PM | TrackBack

For more info on working with tubing, you might want to check out this Ron Covell video, available for rent here:

or for sale here:

Posted by: TJIC at May 5, 2005 08:41 AM

WOW!! I have a JD^2 tubing bender and I've yet to complete some of the bends mentioned here. Very nicely done and explained.

Ed T.

Posted by: Ed Tapanes at May 6, 2005 11:33 PM

Great Article, One question; I have heard that if a pipe is filled with sand prior to bending it will help prevent kinks. Any truth to this?


Gary D.

Posted by: Gary D. at May 7, 2005 06:09 PM

On 5/7/05 4:09 PM, Gary D. wrote:

>Great Article,


>One question; I have heard that if a pipe is filled with sand prior
>to bending it will help prevent kinks. Any truth to this?

Yeah, I've heard this too. I haven't actually done it with steel, but with PVC pipe that I bent using boiling water. I've worked with a few people who have done the sand method on tight bends with steel pipe, and they say it needs to be packed tight and capped before you bend it. If you're going to heat it, you'll want to drill some small holes in the caps so you don't end up with a pipe bomb or a rocket.

Posted by: Hal Eckhart at May 7, 2005 08:24 PM

Darn nice Hal! Of course, it takes true skill, talent and art to do it well (and you have them all). Not just jigs and fixtures.

Your PITA pal,


Posted by: Derek at May 14, 2005 09:52 PM

Well done article.I was thinking of buying an hydraulic pipe bender but after reading this I have decided to try some of your methods to bend tubing for making the front suspension for the conversion of an ATC(three wheeler) to an ATV(four wheeler). Thanks for a job well done.

Posted by: Tim Jones at August 14, 2005 10:21 PM

hello, great website...I need some info...heres my stock...54"x 6.25"x .104...I need to make a beam (C-CHANNEL [ ) THE OUTSIDE DIM. HAS TO BE 3" FROM THE CENTER OF MATERIAL..WHAT DIM. WOLD BE MY BEND LINE? I USE TO HAVE THE FORMULA...CAN NOT FIND IT....THANKS MIKE R. MICHIGAN


Posted by: mike rossbach at October 6, 2005 07:31 AM

hello about using sand to bend pipe....use only baked or dryed sand....if not the moisture will expand and explode the pipe!!!

Posted by: MIKE ROSSBACH at October 6, 2005 07:35 AM

thanks, that chart has saved a lot of time , 'caus before this i use to do it with trial and error method. i jus wana know how to bend pipes of 18mm dia or metal flats of 6mm thick in large smooth curves.

Posted by: Glenn Fernandes at October 17, 2005 03:05 AM

Hi Glenn,

Yeah, trial and error is how I started. I don't know about metric pipe sizes and strength, but I imagine that you could just convert the dimensions and get close to what you're looking for. Close is usually close enough. If you do come up with some data, I'd be happy to post it here.

As far as I can tell (by poking around on the web) nominal 18mm pipe is the same as nominal 5/8" pipe. Of course I've never seen 5/8" pipe, and I can't find it in any catalog or book I've seen, so I don't know how big it really is.

6mm flats would be real close to 1/4". You have to overbend that quite a bit. It's also possible you'd run into some irregularities in how much it springs back, especially if it's hot rolled. Although it's not hard to tweak it by hand.

Posted by: Hal at October 18, 2005 12:52 PM

Great ideas - and, like most really good ideas, blatantly obvious once someone tells you....thanks...will be now able to FINALLY make my shower curtain over the round spa bath.....

Posted by: Andrew at February 24, 2006 03:50 AM

Hello Hal,
First exellent page, you should be a writer. I have a question for you, I have a custome recliner chair design and I am not sure wheather to use wood or steel piping. Myself I think piping would last longer and be sturdier. What do you think?

Posted by: Michael Phelps at March 26, 2006 11:22 PM

>First exellent page, you should be a writer.


>I have a custome recliner chair design and I am not sure wheather to
>use wood or steel piping. Myself I think piping would last longer
>and be sturdier. What do you think?

Well, I'm no expert. I've only made a few chairs, and the only one worth mentioning was supported by a very heavy-walled 1-1/2" steel tube wishbone.

Steel can certainly be long lasting, as long as it's designed and welded properly. Otherwise, you could get metal fatigue and end up sitting on the floor. I don't really have an idea about how you might size the tube or pipe, except perhaps to go look at a recliner that's similar to what you're thinking about and imitate it. And keep in mind that most commercial furniture is designed to be just barely strong enough to last a couple of years at the most.

Posted by: Hal at March 27, 2006 07:54 AM

very good page!!!

Posted by: at April 7, 2006 11:18 AM

Hi, yes, this is a great website.
I'm trying to figure out how to make some 3" radius bends (without kinking) using 1/2 copper water pipe. I've heard mention of a low melting point metal called ceraben (I think this is how it's spelled) but I can't find a source for it. Do you know where I could purchase some?

Tony Tammer
S.F. Bay Area

Posted by: Tony Tammer at April 22, 2006 01:38 AM

Hi Tony,

No, I don't know anything about the metal you mentioned. It might be possible to bend copper like this, but it would take some pretty specialized equipment. You might try the folks at R&B Wagner ( to see what they know.

Or you could try solder. It would be a way to test if the idea even worked.

Good luck

Posted by: Hal at April 22, 2006 06:42 AM

I agree with the others, this is a great resource.

Does anyone have any experience of the degree of overbend required for 316 stainless steel pipe?

I have to do quite a few bends in 1.25" nominal bore 316 schedule 40 for the boat I've built. (It's built more like a battleship than the old sailing yacht 'Spray' that it's supposed to resemble. :)

Posted by: Ged Haywood at May 17, 2006 12:42 PM

Hey Thanks for having this site. Very useful tips.

Posted by: Jeff Gibson at May 20, 2006 02:53 AM

HI Glenn, thanks for sharing your knowHow. You gave me the will to go forward with my projects.

I will be using 1 inch SS (316) tubing with a wall thickness of 1/32 for a bend radius of 8 to 10 inches. Do you have any recommendations before I go ahead ??

Posted by: Gilles at May 20, 2006 05:25 AM

great site for learning. I did learn a thing or 2 or 3 or 4!!!

Posted by: MGooding at June 23, 2006 03:07 PM

stumbled upon your site...
a few further tips.
For Aluminum!
If you're bending aluminum your best luck for bending is a 6061T6 or softer as the harder the aluminum the more likely it will crack or break during bending... a mandrel is usually needed also... I've never tried sand... it kinda scares me actually.
I have found a 3/4" to 1" tube to be the largest most favorable tube diameter size to bend... even then, a 1" tube may need to be mandrel bent.
Aluminum ages on the shelf too, it gets stale like potatoe chips, and it's hardness character changes. So you typically need fresh soft aluminum when bending radiuses that are pushing the limits of the tube.
Glenn has done an awesome job of outlining how to bend metal tube, my only further warning is that bending metal/aluminum tube is a bit of an art and Glenn makes it sound pretty straight forward, where I have screwed many pieces of metal before finally getting it right.
You also want to bend metal cold as when it is hot, yes it will bend real easy but, heating up hot all across the area you need a radius can be tricky and hot spots are typical... so you end up causing a kink at the hottest spot and therefore not an even bend as wished and as designed with the jig.
I do jeep accessories and the tube wall thicknesses are heavier than light duty stuff like muffler tubes, so remember also, heavier wall thicknesses make it a whole new world... and mandrel bending for large diameter tube may be necessary (sp?).

Posted by: Grant Cole at July 19, 2006 04:31 PM

Good website.

Ive been using sand for about 20 plus years, it is an old school technique, and is low tech, but just the same, if you do it right, will produce mandril quality bends, even better? if it is mastered. and you can bend contenuous complex bends this way, all along the stick.

Reason that it works is that it translates energy to the opposite side, you push on the bottom, you push on the top too.

As long as the sides are supported, it works very well.

I have pushed this concept to the extreame, and never had an "expolosion." though I once tore the seams a few times, and the packed sand mearly poured out as soon as the steel gave way.

once I rotated the seam to the inside of the radious, tearing ceased.

one trick is to pack the sand very very tight, using very fine sand. but, it is very time consuming, as drying the sand, screening the sand then packing it

Posted by: robert at August 2, 2006 02:50 AM

Hey thanks for this website. It really helps to know you don't have to have all those expensive tools to bend and shape metal.

Posted by: Jeff Gibson at August 16, 2006 09:35 PM

Hal -

I just wanted to thank you for keeping this information posted and maintaining it - your tips, insight, and experience go a long way in helping others (mainly myself) work this difficult medium with ease. Thanks again.

Posted by: Jeff Nelson at September 7, 2006 12:06 PM

I tried to find a shop that would bend a cast iron putter neck from about 70 degrees to 78 degrees. they said it sould break. I thought that some heat would help to protect it from breaking. Could I try it or should I try to find a fabricator that might do it for me?

Posted by: bill temple at October 5, 2006 11:58 AM

Hi Bill,

My first inclination is to say it will break no matter what you try. That's if it's really cast iron. I don't see how a "putter neck" (whatever the heck that is) could be cast iron unless this is just an ornamental piece. If it's cast, it's more likely steel, which is a lot more ductile. Cast iron is super brittle. The usual way to get iron for casting is to bust up old radiators with a sledge hammer. It doesn't take much to reduce them to a pile of shards. If the putter neck was cast iron, it would likely go sailing off in the general direction of your ball after a couple of smacks.

One more thing to consider though: If you heat it up, you'll destroy the temper. So it would have to be heat treated again to get it back to where it was. This isn't a topic that's been discussed on my local blacksmith's email list. If you do ever figure it out, you might have a whole new career opportunity.

Are there any golf club smiths out there?

Posted by: Hal at October 5, 2006 01:32 PM

Wow! Great job on the explanations. Exactly what I was looking for. Thanks a bunch for taking the time to write it all out and provide the photos.

Nelson B.

Posted by: Nelson B at October 12, 2006 07:09 AM

hi there, great page! fully useful and helping. anyway I was searching the web before finding your page and came unpon a guy who bent some aluminum tubing whit a wood jig just how you did, and to get rid of any deformation he got water inside the tube and freezed it with dry ice to work like the sand mentioned on the previous question. Do you think this would work for 1" , 1-1/4" or 1-1/2" round tubing and 4" Out Diam. with an 20°-30° bending angle. would that make it less likely to deform?? thanks and im writing from venezuela!

Posted by: Guillermo at January 2, 2007 12:31 AM

freezed it with dry ice to work like the sand mentioned on the previous question. Do you think this would work for 1" , 1-1/4" or 1-1/2" round tubing and 4" Out Diam. with an 20°-30° bending angle. would that make it less likely to deform?? thanks and im writing from venezuela!

Posted by: Guillermo at January 2, 2007 12:32 AM

Hi Guillermo,

I have no clue if the dry ice method would work. It sounds like an awful lot of trouble. Making a small radius bend in tubing that size is outside of my expertise. There's a place (rather far from Venezuela) that sells bent tube and pipe elbows that are used to make railings. I'm under the impression that they use a mandrel inside the pipe for this.

One other thing about bending aluminum. Try to stay away from 6061 alloy; it's too hard to bend. And if the hardness is still too much, you can anneal it by heating to just under the melting point and then letting it cool as slowly as possible. Sometimes I use a Sharpie marker and scribble on the back side. Once the marks completely dissappear, it's nearly hot enough. But try not to hit the marks directly with a torch, or you'll stop too early.

You could also bend it hot, but that's pretty tricky. If it's too hot, the metal will break apart like clay.

Buena Suerte!

Posted by: Hal at January 2, 2007 11:47 AM

this is great I have some 2" to do all 90` and this could do the trick great idea saves $200-300 for a hydrolicthanks great site

Posted by: byron at February 17, 2007 11:29 AM

I ahve to bend a metal pipe. It is part of a lowering jack for a cargo trailer. It has lips and is too wide to come out of the hole. Do I need to file this? What tools could I use to bend the metal so it will fit through the holes and come out. I can't any money on this venture. I have some basic tools already. Any ideas?


Posted by: stephen sistare at March 1, 2007 12:01 PM

Hi - thanks for all these great tips 'n' tricks.
To those who is looking for a "fill-the-tube" solution without sand, try looking at this site:

Low melting-point alloys - 'fusible' alloys - find uses in all sorts of application. Perhaps you need to hold a delicate component of an awkward shape?  Or to bend a tube or section without kinking?  Or you need a fusible safety device?  The 'MCP' range of alloys holds the key to these and many other applications.

Keep up the good spirit ;-)

Posted by: Rogert Münzberg at March 4, 2007 06:24 PM

I am trying to straighten an earls fork from a BMWcycle. the tubing is tapered and ovoid . There are welded joints for the axle and pivot point elbow.
The staight lower section 'un-bent' satisfactorily using the front of my tractor, chain for holding and a cheater bar. The upper section of the unit seems to have a compound bend or twist. I have cut the vertical units apart from the triple tree to work each side alone.
What suggestions do you have for my holding end for a twisting "un-bend" (assuming I get it anchored at the other end).
If you have time email me . I plan to try it soon. Jon

Posted by: Thornton at March 28, 2007 08:16 AM

I am looking to bend a piece of 2" copper into the shaoe of an "S". I have practiced with pieces of 3/4" and every time it creases. Do you have any hints or advice that might help? Thanks. Great site!

Posted by: oldtoyotaboy at April 30, 2007 10:35 AM

Anyone have any ideas on bending 4 1/2" ID Stainless steel tubing..used for marine exhaust???

Posted by: Shaun at May 23, 2007 09:49 PM

For those who are trying to bend pipe: I am a professional steamfitter/pipefitter/weldor of 23 years and an amateur blacksmith.

I installed a modern forced lubrication system on a 1912 vintage powerplant, on the Ocoee River in Tennessee. The pipe was 3/4" and 2" schedule 40, 316L stainless steel. The specifications called for as few welded joints and flanges as possible.

I cold bent nearly every piece of this job with a Greenlee electric conduit bender. It worked very well until trying to bend the 2" to near 70 degrees. At that point, the bender was simply not strong enough to continue the bend. On the 3/4" pipe, there was no problem.

I am also an apprentice instructor at my local union. I have full intention of teaching these kids how to bend large heavy wall carbon steel pipe using the sand/heat/two posts method from many decades ago.

For the really large stainless stuff, I suggest a roll bender.

Posted by: David at June 3, 2007 01:05 PM

do you have any info on or about how to make your own square tubing benders capable of bending 3" tubing or anything smaller, with hydraulic assitance

Posted by: Martin at July 6, 2007 08:10 PM

Ive been looking and looking for ways to bend a 1" exaust pipe for a tractor and this is the first place i have been able to find any information thank you.

Posted by: Mike at July 10, 2007 01:37 PM

I would like to learn how to bend tubing. Maybe there's a good book (Formula for offset,ect.) you can suggest to me.It can be in english.


Chris from Québec.

Posted by: Chris Savard at August 21, 2007 07:38 AM

re sand; I used to work in an oil refinery with lots of straight pipe. The boilermakers used to fill small diameter pipe with sand,cap it and wrap it around a 3- 6 inch pipe to make a cooling or heating coil. They looked machine made. They had lots of heavy equipment so I doubt if they heated it.

Posted by: John at October 22, 2007 04:46 AM

I am wanting to make some circles with soft copper tubing (1/4" to 3/4"). Do you have anything in you lineup of jigs that could be used to do this.

Thanks, Rod

Posted by: Rod at October 22, 2007 06:25 PM

Filling metal tube or pipe with sand prior to bending is absolutely a great way to keep the material from crushing during the bend process. A fair amount of heat is necessary...better to use a rosebud to make certain heat is not concentrated in one area only...keep heat ahead of the bend on the pipe or tube. If using seamed tube, make sure seam is on inside of raidius. Can be used with carbon, stainless, aluminum, and brass. Slow process but doeas work very well.

Posted by: Terry at October 27, 2007 03:27 AM

In the mid sixties we bent the tubing for race car bumpers, push bars, tire racks, etc. by taping up one end of the tube and filling it with dry sand from the kids sand box. An old window screen got rid of the trash. The trick is to put about a cup of sand in between each packing until it is full, and tape up the end. We did not apply heat, only lots of muscle. You must use a smooth radius to bend it without collapsing. We used a tree with a fork in it close to the ground. Defineately not high tech, but one of those racecars we built has returned to the track with the original bars bent this way. I still use this method to this day when neccesary.

Posted by: Allen at October 28, 2007 08:10 PM

im making my sons a go kart and the roll bar needs bending now being from Australia we work in metric the stock is 25mm nominal bore x 2.6mm wall would i be able to bend this stock around jigs
thanks Adrian

Posted by: adrian at November 14, 2007 07:28 PM

Hi Adrian,

That looks like what we'd call 1" pipe. It should bend pretty well, but I'm not sure how tight you could go without resorting to the sand method that some have mentioned above. One thing I would do is use a cheater bar, otherwise the tangent of the pipe that you're bending from will be slightly bent also. This always happens to some extent, but it's a little more noticeable with heavier wall thicknesses.

By the way, posting here in the comments isn't the best way to contact me. There's a link for me

Posted by: Hal at November 15, 2007 08:49 AM

an other way to bend piping without high cost is to rent the bender.

Posted by: Robert at December 28, 2007 09:24 AM

Loved the article. I am a novice metal worker and am interested in duplicating some of the decorative, light weight metal projects seen at candle stores like Illuminations. The steel rod is small in diameter but the radius of the candle holders varies and its small (i.e. 2" - 12" generally). Your article seems to tackle the larger bends. Is there equipment readily available that a garage hack could add to his inventory that would produce the results I am looking for?

Posted by: Randy at January 6, 2008 07:10 PM

There are almost too many ways to do this to list. The only commercial bender I've bought is a really crappy Harbor Freight one for $50. The dies that come with it are more useful than the bender. I've used a Hossfeld bender and I've seen one made by Di-Acro. They are all useful to a point, but also somewhat limiting.

My thought would be to just play around with the material and see what you can do. Material up to around 1/4" can be easily formed on the horn of an anvil with a hammer. Or with a short piece of pipe clamped in a vise, you can bend rings. Just vise-grip the material to the pipe and away you go. Or attach a couple of bolts to a table for pins...

The best way to get a sense of it is to get your hands dirty and see what happens.

Posted by: Hal at January 6, 2008 10:49 PM

this is what the web should be about, one man sharing his knolage with others. great advice & tips! thanks

Posted by: wazz at January 28, 2008 12:52 AM

Great article! I experimented with tube bending after I got a quote of $11,000 for bent tubing for a car project. Check out the TwinTech at

I'll bookmark your website for reference on future projects.

Thanks, Dave

Posted by: Dave at February 6, 2008 08:36 PM

.re annealing aluminum try marking one side of the part to .be annealed with the edge of a bar of plain laundry soap gently heat the opposite side of the aluminum untill the soap streak turns cholate brown move flame on to next area and repeat allow job to cool . result will be nice .soft alluminum hope you find this tip half asgood as the things ihave learnt from you .thank you

Posted by: .william at June 12, 2008 07:41 AM

good time
dear sirs,
how can i do bending a seamless steel tube material ASTM A213grade T22 OD 50.8 mm ,thk 6.5mm ?
radius of bend(CLR) is 50.8 mm and degree of bend 180.
that means a U tube with a 2000mm LENGTH OF each leg.
best regards

Posted by: kheradmand at September 18, 2008 09:37 AM

I have no idea. Find out if someone in your area does rotary bending. Or check out
and search for item 4691. It's pretty close. Unless they already have the right size die, it would be very expensive to make one for your exact specs.

Posted by: Hal at September 18, 2008 09:59 AM

The info is really good. I play with metal building bbq grills. My dilema is a tank that is 20in diameter, I cut a door lengthwise about 12 x 36. The door does not close snug and the lower end does not follow the curve of the tank leaving a gap along the bottom. I need to bend the bottom of the door, it is 1/8in steel that has been rolled. Any ideas. Thanks! Jim

Posted by: at September 24, 2008 09:13 PM

the info is good but my problem is im fabing a ram air induction kit for my trans am and im trying ta bend a 3in pipe into a 90 degrees wid out it kinking or flaten out
WHAT DO I DO???????????

Posted by: sam at October 7, 2008 11:53 PM

The short answer is you can't.
Try this for some cheap options:

Posted by: Hal at October 8, 2008 07:30 AM

I bent a couple of long pieces of PVC pipe by climbing up on the roof and lowering them into the chimney to heat them up. It worked beautifully. They were large radius bends.

Posted by: John Lang at October 29, 2008 09:24 PM

I'm about to build plywood jigs to bend 1" aluminum, square, tubing to create 6' diameter circles.

I plan to mechanically join individual bent pieces to create the circle. As a total novice I'm using this article as my bible.

Do I still need to calculate the jig radius to include spring-back ? Or, since the 2 bends will be bolted together to create a circle would I bend them to the desired radius for the 6' circle and then force the sprung ends back to that radius as I join them .... then they will hold each other in tension as a circle ?

If the jig does need to be smaller someone please offer advice on how much smaller for 1" aluminum.

Posted by: Kent Scheer at November 3, 2008 08:57 AM

Yes, the jig does want to be smaller. How much depends on your stock, which is a bigger variable with aluminum than steel. As a scientific wild-ass guess, I'd say about 30" radius to start. It might be bigger or smaller. And don't forget to add at least 6" extra on each end, which will be mostly flat.

It's always easier to unbend it a little than to tweak it a little tighter. Clamping and welding will help hold it in shape a bit, but just bolting may not work that well. Allow enough time to redo the jig once or twice.

Posted by: Hal at November 3, 2008 09:40 AM


Thanks for such an exceptionally swift response and for your clarifications!
My project is time sensitive because we have very few OK days left here in Minnesota for me to accomplish this in my garage, so your quick reply is much appreciated.

Posted by: Kent Scheer at November 3, 2008 10:09 AM

I want to bend 40mmx 10mm mild steel on its edge without heat, i have done this but not happy with the end result. its only a gradual radius over a 2 metre span, can you advice.

Kind regards. Gary, Manchester, England.

P.S. Love your site

Posted by: gary at November 7, 2008 09:07 AM

What's your thought on bending 3/8 steel rebar into a radius? Have used an oak tree in the past but the arc is rough. Material used to make a garden arch welding cross pieces,etc. I'm assuming the steel is stamped making it harder than annealed.

Love your info and presentation.

Thank you.

Posted by: RW at January 20, 2009 01:36 PM

Rebar is hot rolled, but has about double the yield and tensile strength of ordinary hot rolled rounds. It bends fine, but it's harder and will be a little more uneven due to the texture. I made an expensive coffee table out of it once. Up to 1/2" is pretty easy to bend, even without a tree.

Posted by: Hal at January 20, 2009 02:28 PM

im ainstalling stainless steel hydrolic tubing im getting it done but id like to minimize the crop offs most bends are 90s . im using 3/4" and 1/2" tubing. i cant get it exact is there a procedure i can follow

Posted by: marty at January 26, 2009 10:11 PM

Thanks for posting this "trick of the trade", it works 100% and saved me a heap of time and money.



Posted by: at February 19, 2009 05:49 AM

Hi Glenn,

Can you advise best option to form a 10' length of copper pipe into a full circle? If so reply to my supplied email address.

Im in ham radio its for an antenna.



Posted by: Berne at February 20, 2009 12:12 PM

I was hoping you guys could help me by giving me some suggestions on fabricating a curved hand rail.

I was thinking about making curved stair handrails from 2.5 in diameter tubing. I need two, one for the outer radius of the staircase and another for the inner radius.

Outer hand rail: Length 14 ft, Desired bend radius 7.5 ft
Inner hand rail: Length 8 ft, Desired bend radius 4 ft

Making jigs seems impractical for such large radii. Any suggestions?



Posted by: Lili at March 4, 2009 02:14 PM

Thanks for this site!
I am trying to make my own green house out of Galvanized structural steel tubing. I want to use 1.66" to 1.90" tubing in about a 14 gauge. Is it feasible to bend this material by hand with a well built, well mounted jig using a cheater bar? I do not need to make tight radius bends.

Posted by: Zac at March 5, 2009 10:35 AM

The two biggest things you need are a table bolted to the floor and a jig that's strong enough. You can often get by with mdf or plywood, as long as you use a strip of steel on the edge facing the tube to be bent. Otherwise, the jig will split. Square tube is a little easier on jigs.

Good luck.

Posted by: Hal at March 5, 2009 11:39 AM

I would like to build a 5" square jig similar to yours. any chance you could send me some dimensions/photo to help me out.

Posted by: Dan at March 13, 2009 08:54 PM

Northern Tool or Harbor Freight sell 16 ton Hydralic benders with mandrels from 1/2" to 3" for about $200. (for round schedule 40/80 pipe) If your bending the big stuff get a hydralic.
For big arcs I mount a micrometer on the top and make a bend every few inches. The micrometer measures the deflection. It is more accurate than counting the number of pums on the jack handle.

Posted by: Kendall at April 8, 2009 10:21 PM

I enjoyed all the communications here.

I have bent aluminium extrusions before for handrails and window frames I used sand and it does the job good.
For larger size extrusions I have a problem.

I was interested if someone has heared of resin fillers ? I came across this site in my seraches-
Take a look at WS8- high density fusible alloys for tube bending operations.
can you tell me if this is practicle ?

If not this specific brand then any other kind of Resin ?

Thank you,
Aviad Wolff.

Posted by: Aviad Wolff at April 12, 2009 01:53 PM

hello i am going to be making stainles steel handrails for a boat.there wil be some right angle bends.
the size of tube is about 25mm o/d what would be the best way to bend that could i use a normal pipe bender with a former or could i do it by hand.

regards alton

Posted by: alto taylor at April 19, 2009 03:02 PM

For small radius bends in round tubing, there's not a good way to do it by hand. Usually what's required is "rotary" bending, which uses a mandrel and a big machine. If you want to weld on a bent elbow or hire somebody to bend it, the best place I know it R+B Wagner (

Posted by: Hal at April 19, 2009 03:28 PM

very good article and advice, loads of good info. i need to bend 1" solid aluminum rods (unknown type for now)that are connected to each other separated by about a foot or so. i am unable to build a jig because the rods are welded in a fixed position on some wheelie bars. if you can imagine a capital "U", this is essentially what i am working with, but with the bottom of the U being square with its corners welded. the tops of the U need to come closer to each other by about an inch. i thought about using a ratchet-type tie-down by wrapping it around the end/top and cinching it down, drawing the two ends toward each other (hopefully). my concerns are: 1. i may not be able to ratchet much because the rod is so strong. 2. if i can get it to bend this way i am unsure on how far to bend it....only as far as where i need to go? (and will then undoubtedly bend back into its original position). if i go too far and it they bend toward each other too much, its going to be hell to pay i'm afraid to pry them back apart. 3. should i apply heat? i really don't want to screw with it too much because i don't want it to break or become weak. any advice you have will be much appreciated...feel free to email....thanks, mike

Posted by: mike at April 21, 2009 07:13 PM

After reading much on the 'net today I decided to develop my own method, much simpler than everything I've read.

I needed 1" pipe with two bends in it, each 90 degress, to make a square 'U' (replace a support in a bicycle rack that wasn't tall enough).

I laid the 1" steel tubing (a cross member from some old scaffolding, really sturdy stuff) perpendicular across two 2x2's about 8" apart on the sidewalk. Then I proceeded to hammer away with a really big hammer a section of the tubing about 4" across. After about 15 minutes I had a *slight* bend in the pipe but with a 4" flat section. This weakened the area enough that I could put it in a vise and pull (hard) to complete the bend.

Piece of cake!

Posted by: Carbon Sink at April 23, 2009 11:34 PM

thats good worke

Posted by: abd at June 19, 2009 08:10 AM

Does this method also work with c channel?
If not, how can you bend c channel?
How tight can you bend it?

Posted by: Ben at July 7, 2009 02:45 AM

Channel and angle are both notoriously hard to bend. I've only ever done it on very small profiles; less than 1". I've had angle bent by people with big equipment, and the results aren't always pretty. The forces required are so great, that it can get deformed.

Posted by: Hal at July 7, 2009 08:02 AM

that's all good stuff. Remember, heat covers a multitude of sins. Or something like that. Rosebud, open forge, even MAPP torch can make things a whole lot bendier. Sand inside is good. tiny vent holes are good. OR, when capping the ends just use a generous amount of duct tape. Keeps the sand in but won't let enough pressure build up to explode if you get steam. Just don't heat too close to the ends. All you're trying to do is prevent the tube from collapsing. It isn't pushing on the ends very hard. What's even better is dumping a bunch of dry graphite in and mixing it with the sand. Makes the sand slippery inside the tube. Wax is also a good filler if you've got a bunch and will bend cold. Then after bending, put some heat on and melt out all the wax if you need it empty. Or just leave it in there. Depends on the end use. Got some big old tension springs? Garage doors, trampolines, etc. slide the tube in, bend away with the spring around the bend, all good. Want to get fancy? Bend away with whatever you can use. Seal up both ends afterwards. One cap is solid, the other is an air fitting. Heat up the kinks with a rosebud to red/yellow (for steel) and then inject air at 120 psi. POP! out comes the kink. Course you can go too far and have a blowout or an aneurysm (fat spot) but thems the breaks.

Posted by: Ralph at August 24, 2009 08:06 PM

Zac asked a question that is the same as mine. I want to bend some sections of pipe for greenhouse framing. What I need is a 180 degree upside down U shape. There will be approximately 3-4' beyond the end of the bend. Your jig for 2" pipe semicircle calls for 108" for a finished length of 173". Is the jig to be and actual 180 degree semicircle? The pictures of your jigs look very different. I think they are for smaller things possibly. Could you post a sketch of the jig with dimensions that I am in need of. Thank you, Gene

Posted by: Gene at August 27, 2009 05:10 PM

A couple of points here. If you want to contact me, try the email link on the main page, which points to
I'm not sure how to phrase my chart above better. There's nothing about length or semicircles in the chart. It's all radii. 108" is the radius of the jig and 173" is the radius of the bent tube. A jig to bend a semicircle in one shot is going to be huge. Or am I not understanding your question?
And btw, it's 2" tube, not 2" pipe. I don't think I'd even attempt that without weight training.

Posted by: Hal at August 27, 2009 06:16 PM

I need to put a few sharp bends in 3/4" square steel tubing, but I can't seem to find a jig to accomplish this feat. I was thinking, could I tape a 1/8" copper wire to the steel tube, then bend it around a pole? I have a steel pole in the backyard that is cemented into the ground and is relatively free of obstruction. Any other ideas would be welcome.

Posted by: Doug at October 30, 2009 05:50 PM

Can some one help me with the tolerance on thickness for 180 deg bends. My email id is

Posted by: Abbas at January 28, 2010 01:54 AM

Well I am gonna give this method a try, I can't be paying for specialist equipment as there are limited funds now but luckily I have loads of space and the basic tools.
Should I take any special precautions for using Stainless Steel tubing? Thin walled with external diameter of 76mm or about 3 inches - (quite heavy stuff) It has to be inox because it will be polished and lacquered afterwards for outside applications.
I am only talking about 30 degree bends for the moment but it will eventually go to 90 I suppose as I cannot stand ugly welded joints.

Posted by: Mister John - Belgium at February 18, 2010 12:08 PM

Well, good luck. That's way over my head. Stainless is a lot harder to bend, and that's too big for me in any case. Without big machinery, you won't be able to have a tight bend. I'd have to guess that it would be a 5 to 10 foot radius or it will kink.

If it's going outside, you're going to want to avoid contaminating the surface by contact with steel, or you will have problems with rust.

Posted by: Hal at February 18, 2010 02:08 PM
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