Question: Bending Large Aluminum Tubing

[Victor Bravo]

Can anyone tell me where I can find reliable numbers for the minimum bend radius on large 6061-T6 aluminum tube or pipe, something like 5 or 6 inch diameter, and at different wall thicknesses? I need to put a bend in the frame of an experimental off-road vehicle. I know I can cut and weld, but there are also areas where I want the curve. I figure someone in aviation might know this.

Thaanks in advance -

[Mike Switzer]

I don't remember what alloy was used, (and if I can find my copy I will let you know but I probably can't get to it until next Wed due to a business trip)

But I have a Navco piping catalog & engineering data book from the 40s or 50s someplace that covers that sort of thing, I believe it covers stainless, aluminum, and a couple grades of steel. Probably cast iron also, but you couldn't bend that.

I see them occasionally in antique stores, etc. I think it might have been called a "Navco Pipe Datalog"

[Mike Switzer]

I think Crane might have published something similar - I definitely remember reading about allowable bend radiuses, etc.

[CraigCantwell]

Page 3 of this pdf will let you calculate it. The allowance is going to be different based on using an internal madrel or without and what temper you are using.

http://www.sapagroup.com/pages/522736/Brochures/Sapa%20Pipe%20and%20TubeTechnical%20Inserts%20June %202011.pdf

[Victor Bravo]

Thank you Craig ! There was a chart on that page, with a formula easy enough for a blockhead like me to figure out.

For 6061-T6 tube, 5 inch OD by 1/8 wall, you need a minimum bend radius of 18 inches at the centerline. For a 6 inch tube, the minimum radius goes up to 21 inches..That is EXACTLY the information I needed. Thank you again.