# Bending stainless pipe



## nosco (10/4/16)

I've got some 1/2" stainless to make some pickup tubes. Just wondering how to bend it. My cheap Aldi pipe bender's got no chance. Is stainless OK to heat up? Even then it will probably still kink and is going in a compression bit. Any one have some tips?


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## Grott (10/4/16)

How big a bend for these pickup tubes?


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## nosco (10/4/16)

Maybe 45 or maybe a gradual curve. Depends on what i can do.


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## manticle (10/4/16)

I've heated and shaped thin stainless (2-3mm rod) before but anything thicker and it's pretty difficult. That was solid rod for mountmaking - I can imagine tube being more difficult to do correctly without compression.

I think you'd be better off finding/borrowing/buying a better bar bender.


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## MHB (10/4/16)

There are two very different things called 1/2" stainless, Pipe and Tube. Pipe is 1/2" (nominal) Inside, Tube is 1/2" Outside diameter.
Lets assume you mean tube. I used a pair of Ridged 1/2" copper tube benders for years to bend tube, and have recently upgraded to a specialist stainless benders.
Then comes the question of wall thickness, the thicker the harder it is to bend, also whether it's annealed or not.

Pipe is really hard to bent especially at tight radiuses, it's usually easier to cut and weld to get the shapes you want, or thread and use fittings.
It is possible to bend both, one way is to pack the pipe with dry sand (a rag packed into each end stops the sand coming out - by packed I mean tamped down really hard), then heat to yellow heat with an oxy torch (LPG wont get hot enough) and bend - the sand helps the pipe keep its shape. Can do something similar with a piece of Aluminium round bar that is a close fit if you want really tight bends (soak in Caustic Soda solution after bending and the Al will dissolve)
I'm sure there will be a YouTube video out there somewhere.
Mark


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## hotmelt (10/4/16)

You could also try filling with water and freezing.


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## nosco (10/4/16)

MHB said:


> There are two very different things called 1/2" stainless, Pipe and Tube. Pipe is 1/2" (nominal) Inside, Tube is 1/2" Outside diameter.


Couldnt remember which was which from my YouTube training. Whichever it is everything fits. Ive got all the parts i just have to put it all together. I scored about 2 metres worth so i have plenty to play with.

Ive got a Bernzomatic map/pro torch so ill give that a go first. Ive got to solder on a flange first then ill have a go.

Thanks all.


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## AJS2154 (10/4/16)

Yep, what Mark said.....pack it with sand then heat that bad boy up. Best way to do it. Stops it collapsing and works every time.


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## Kev R (10/4/16)

Proper ridgid brand tube bender is the go, last place i worked let me borrow one, think they are around $200 mark. Now i make do with a cheapy from bunnings. Ment for copper, struggles with S/S but does the job.
Packing tightly with fine dry (must be dry)sand and heating is ok . You will need somthing to bend it around, a short piece of pipe the right radius tack welded to your work bench is good.
Getting it shiny again will be a bit of a mission. Also most stainless avaliable is low temp not sure getting it red is so good, tech stuff not likely to be an issue. Don't get it to hot or the oxy in air will attack the metal.
Kev


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## nosco (10/4/16)

Kev R said:


> Getting it shiny again will be a bit of a mission. Also most stainless avaliable is low temp not sure getting it red is so good, tech stuff not likely to be an issue. Don't get it to hot or the oxy in air will attack the metal.
> Kev


Yeah i was thinking about the cleaning plus i wasn't too sure about heating stainless. Glad i asked. I see if i can track down a better tube bender.

Edit: tube, not pipe. ?.


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## Batz (10/4/16)

I bend a lot of 1/2" stainless tube with my work, mostly high pressure heavy wall stuff. I do it with a ridgid brand tube bender, it still takes a fair bit of effort from an old guy like me, but it works.

Bad luck your so far away I have several benders at home.

Batz


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## Camo6 (10/4/16)

Is it annealed SS tube? If so, it's relatively easy to bend and I had no troubles bending 1/2" and 12mm into pickup tubes with the Bunglings $40 unit. I was almost tempted to take it straight back the same avo for a refund but I like to feather my nest with tools.


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## nosco (10/4/16)

Not sure if its annealed or not. For the price ill give the bunnings one a go. If not ill try and knock up a (timber) thing to use with a car jack. As usual ive run out of time this weekend so it will have to wait.


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## nosco (13/4/16)

I got a heap of stainless elbows and other bits but thought if i go 180 on the bend then i can use less parts. 
I got the el cheapo bender from Bunnings. Put it in my el cheapo bench vice from the asian ebay hardware store ( who's warehouse is near me . The enamel started chipping of the bench vice and i had to adjust it a few times but it got the job done without sand. El cheapo all the way but its it pretty deluxe for my standards.

I have some kids sand and some 1/2" rod to pack with so i might try it on the next one but pretty impressed with the lack of kinking.

Edit. Spaling.


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## MHB (13/4/16)

If you have a bender now, you wont need sand. Sand is for when you don't have a bender that keeps the tube from flattening or kinking.
Also very handy when you want to bend pipe or heavy wall tube and at smaller radiuses. For pipe you also need heat the pipe is heated until it softens then you pull it around, moving the heated zone along with the bend. 
Mark


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## Camo6 (13/4/16)

Agree with Mark about heating the pipe. All the annealed SS pipe I've sourced comes unpolished. Easy to bend once but needs a good polish to make it shine. Yours looks like polished stainless and won't be as easy to bend with the cheap unit.


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## nosco (13/4/16)

Now that i know how to do it i could do a neater bend if i took my time.
Not worried about the polish unless it will make it easier to clean, more sanitary? I wouldnt have thought so. Thanks fella's.


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## mhunter (28/10/16)

Just my 2 cents worth. I heard if you are doing complex bends in a pipe or coils you are better of packing it with sugar or cooking salt as it is less of a problem if you can't get it all out.


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## Adr_0 (28/10/16)

If you use a bender, try to get it right the first time - when bending it hardens the inner surface, so subsequent bend will be more difficult and more likely to distort the sides and outside of the bend.


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## Lyrebird_Cycles (28/10/16)

Working the metal hardens both the inside and the outside.

Fortunately work hardening in 300 series SS alloys is easily reduced by annealing. You don't need to do a full water quench, for small sections a simple air quench will bring you back to YS around 300 MPa.


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## Zorco (29/10/16)

mhunter said:


> Just my 2 cents worth. I heard if you are doing complex bends in a pipe or coils you are better of packing it with sugar or cooking salt as it is less of a problem if you can't get it all out.


Paul Wicksteed did this for his HEX and for just the reason you said. I've kept that in mind too. His case was for copper though.


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## Maheel (29/10/16)

dont use sugar and heat = toffee.....


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