# Circularising Aluminium Pipe!



## Munty Scruntfundle (16 Oct 2022)

Hi folks.

I have some aluminium pipe, 66 and 44mm (ish) diameter. This stuff isn't top quality, while it serves it's purpose as pipe it's not round. Or I guess it's round ish. 

I could really do with this pipe being as round as possible. Unified? Standardised? Or is that wood?

Both pipe sizes have a wall thickness of 1.6mm so I don't have enough material to remove any. Does anyone have any advice on how this might be achieved? I've thought of making a brass or delrin 'bung' and kind of swaging it, I don't know how successful that would be. The final outer diameter isn't critical so this might work if I don't introduce any cracks.

Has anyone out there had to achieve such a pointless and time consuming exercise?!

Many thanks.


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## Inspector (16 Oct 2022)

I would classify those sizes as tubing and I doubt you will be able to swage them perfectly round or close to it. How much out of round are they and how round do you need, your tolerance? What is the end use? How much of the tube needs to be round and how long are the finished pieces destined to be?

Pete


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## AES (16 Oct 2022)

How long is the pipe length/s? How bent is it now? How deep are the "dents" in it now? What will you use it for?

Depending on your answers to the above, it MAY be simply a question of finding/making a suitable mandrel (from wood - have you got a lathe?) and simply "driving" the mandrel down the pipe with a mallet. If necessary annealing the ali first i.e: coat all over with soap, and heat gently all over with a blowlamp until the soap turns brown. OR have you got/can you get plumbers' bending springs of approx the right size?

As said above, an awful lot depends how long the pipe is and how straight it's got to be. The only "known component" we have at present is that dia isn't all that critical.


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## AES (16 Oct 2022)

Inspector said:


> I would classify those sizes as tubing and I doubt you will be able to swage them perfectly round or close to it. How much out of round are they and how round do you need, your tolerance? What is the end use? How much of the tube needs to be round and how long are the finished pieces destined to be?
> 
> Pete



"Great" minds think alike Pete! I did straighten a length of vacuum cleaner ali tube about 2 feet long using the above method.


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## Fitzroy (17 Oct 2022)

Circularising, circularising, why would you want to do the other thing to an aluminium tube! Too early on a day off and eyes not working.


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## Bingy man (17 Oct 2022)

A lot of work for your project that you’ve not stated the purpose or intended use . Save yourself time and money and the need to purchase additional tools and buy suitable pipe in the diameters reqd. Eg copper pipe is available in 15 22 28 35 42 mm etc , and can be supplied Crome plated. Other tubes eg conduit, seamless tubes, shower poles etc are readily available. All will be round .


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## ChaiLatte (17 Oct 2022)

Seamed pipe or seamless?

If seamless, look at some of the brass musical instrument repairers on YT.

They have shiney balls of various sizes.


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## KT -andy (19 Oct 2022)

Thin tube can be made a bit more rounderer by running a suitable sized open ended spanner round it , or use an adjustable spanner wound down to the size it should be .


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