×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Aluminum tubing strength

Aluminum tubing strength

Aluminum tubing strength

(OP)
I am wanting to manufacture a prototype aluminum ladder. A ladder we currently manufacture uses 1.750 x .750 x .125 6005 T5 channel. I would like to use a 1.750 x .750 x ? 6005 T5 rectangular tube. My question is, what wall thickness can I use on the tubing that would match the strength of the .0625 wall thickness of the channel? Thank you very much in advance for any replies.

RE: Aluminum tubing strength

Try the "Aluminum Design Manual" from www.aluminum.org.  Assuming some other standard isn't applicable to your work, that is.

There are also ANSI standards for various kinds of ladders.

RE: Aluminum tubing strength

(OP)
I am sorry that should have read "the same strength as the .125 wall thickness of the channel"

RE: Aluminum tubing strength

Strength is a relative term.  If you are just wanting similar area and moment of inertia in the strong direction, both 0.064" and 0.080" will do. There may be other factors you need to consider however such as weld size, method of attachment, local crippling.  Contact me if you need some help with the overall design.

ZCP
www.phoenix-engineer.com

RE: Aluminum tubing strength

(OP)
Thank you for the replies. The application is a ladder rail which hangs down at a 25 degree angle, held by a stop block and the ladder  frame at that angle. The ladder rail itself is 47.25" with the fulcrum being 2.875" from one end.

RE: Aluminum tubing strength

First - your initial post has the channel .125 thick but then .065 thick.  Which is it?

Second - if you change from a channel to a tube keeping the width, depth and thickness the same, then the tube will be stronger.

Third - if you halve the thickness but double the quantity, the strength will in theory be the same.  You will have to review the thinner sections for web cripling, shear and local buckling.

Fourth - for a small item as this, go with the same thickness but a tube.  The couple of dollars won't really matter unless you are making a lot of them.  Welding the rungs will be easier in thicker material.  When human life or safety is at risk, don't even think of skimping.

RE: Aluminum tubing strength

You should also consult the appropriate OSHA guidelines for minimum load and size requirements for ladder components.  I think it is 1920.27.

RE: Aluminum tubing strength

(OP)
Thank you all very much! The channel I use now is .125 thick, I want to start using a tube in its place and knew I wouldnt have to have it as thick but just wasnt sure how to figure what I could cut thickness to. I do have concerns about going to .0625 thickness on tube but feel sure that .080-.090 would be more than sufficient. As it stands now the boat ladder will hold 560 pounds with no problem using the .125 channel. Excuse my rambling, I appreciate you folks taking the time to help me.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources