I was just at marigold st Revesby yesterday.
Edcon steel...the place to get those small steel bits to build with .
Just happened to see they had a large range of U bend tubes - Various sizes - in the Mandrel style.....
No Distortion or kinks....
Lovelly for that Extractor you are thinking of building.
Just wish I had asked for a price.
I had just finished picking up a 5mm thick 130 x 750 mm slab for some manifold building (flanges)$ 6.50....and I was shooting off before he changed his mind.

Damm, I usually buy mine from Walkers out near Minto, sorry Mino.