Bending SS tube with heat

[pcampo]

I have 1/2'' SS tubing I found at work. I don't know what grade or thickness. But I am having a little trouble bending it (more so at the ends) into a coil for a post/pre-chiller.

Im thinking of heating it with a propane torch just enough to bend it easily. Anyone try this? Does it work

 

[day_trippr]

Unless you're using a bender, I'd be inclined to believe heating the tubing would only hasten a kink.

You're trying to take a tube and make one side longer and the other shorter.
I don't think heat alone is the answer...

Cheers!

 

[pcampo]

Thanks for the reply day trippr...That does make sense

 

[Randy64]

I use stainless tube at work .035 wall thickness can be bent with a conduit bender.

 

[Stealthcruiser]

I use stainless tube at work .035 wall thickness can be bent with a conduit bender.

1/2 inch diameter?

 

[Randy64]

Yes we use 1/2 and 3/4 OD tube both have .035 wall thickness.


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[Stealthcruiser]

Yes we use 1/2 and 3/4 OD tube both have .035 wall thickness.


Sent from my iPhone using Home Brew

Annealed, I'm guessin'?

And it doesn't kink, on a conduit bender?
That's pretty wild, if so!

Ya' happen to know the alloy, per chance?

 

[Owly055]

The best way I've found to bend without kinking or flattening is to fill the tubing with sand and cap the ends. Fill completely full, and you can cap using various methods, such as a flare fitting or ferrule fitting and pipe cap. This is a trick that has been used for generations, and was popular in aviation for bending chromemoly tubing as well as aluminum. It works! As someone else pointed out a conduit bender is a great tool for getting your curvature. Once full of sand, an ordinary V belt pulley works well also.

H.W.

 

[Stealthcruiser]

I could see that, Owly..........You then have a "mandrel" within the tube.

 

[Randy64]

The conduit bender does flatten it a little but for low pressure it shouldn't matter. I've heard that sand works to stop the flattening also.

 

[Owly055]

I could see that, Owly..........You then have a "mandrel" within the tube.

It really does work...... and you get no collapse. It was used in aircraft manufacturing for many years...... and still is in home building. They also used a resin that could be poured into the tubes hot and would "harden". Not actually hard, but firm enough to provide the necessary support. Then done the tubes were heated and the resin poured out.

Another method that works is a spring that fits fairly snugly on the outside of the tube to be bent........these were made commercially and I have a set of them. Because the spring is round, and of steel the metal to be bent cannot deform. To collapse it has to be able to expand........ which it cannot do. They can be difficult to remove due to the pressure of the tube inside trying to distort but not being able to.

Stainless steel is NOT annealed by the methods used for ordinary steel, simply heating and slow cooling.


H.W.