I was just inquiring about the weight bearing capability of round aluminum tubing for use as a bench,seat, or chair. Similar to the aluminum seats used in doctors' offices and in hospitals. I see that a aluminum and plastic shower bench is rated at 400 lb user mass.

At McMaster-Carr I was looking at 3 ft sections of 1" diameter 0.65" wall thickness as I absolutely do not want the sections to bend at all or possibly break. I suppose that a smaller diameter or wall thickness would or could work as well.

Thanks for any advice, opinions, or answers.


  • $\begingroup$ Does aluminum flex well? Fracture? $\endgroup$
    – Solar Mike
    Jun 13, 2023 at 16:04
  • 3
    $\begingroup$ "I absolutely do not want the sections to bend at all ..." That's not engineering. The tube will bend. You need to specify what amound of bending is acceptable. Note that this is a Q&A site rather than a discussion forum. You didn't actually ask a question. $\endgroup$
    – Transistor
    Jun 13, 2023 at 19:22
  • $\begingroup$ I think you are looking at 1" OD AL tubing with 0.065" wall thickness, correct? How are you going to make the bench table, - arrange the tubings side by side over a span of 3'? $\endgroup$
    – r13
    Jun 13, 2023 at 20:15
  • $\begingroup$ All materials will deform when load is applied. There is no perfectly rigid material so saying you do not want it to bend at all is unrealistic. If you relax things to say you don't want any visibly discernible bend, you then now need to specify how much deflection that would be. Then you can begin crunching numbers. For example, 1/8" defletion over 12" or 3mm over 30cm. You can use your mind's eye for this since it's more of an aesthetic requirement that is more stringent than a structural requirement and therefore takes precedence. $\endgroup$
    – DKNguyen
    Jun 13, 2023 at 21:06
  • $\begingroup$ That is correct 1" diameter aluminum tubing with 0.065" Wall thickness. I was actually going to cut the 3' ft tubing into two 18" sections and two 14" sections. Arranged with the two 18" sections parallel to each other and the two 14" sections dividing them at both ends for a 18"X14" rectangle tig welded together. 64" of aluminum tubing would be needed for this design. I hope that this makes sense. $\endgroup$
    – Spencer
    Jun 13, 2023 at 21:14


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.