Welding: How to choose proper size steel tubing | The Garage Journal

I recently picked up a miller syncrowave 180sd off craigslist, only 11 arc starts! Time to teach myself how to tig!

Anyways, i have a few projects coming up that I'd like to do and have been looking for some sort of formula /chart/math/etc to figure out what size tubing I'll need to use to properly support what I'm building. For example, if I know that the max weight a table will need to support will be say 500lbs (nearly 2x what it will ever actually support unless two big guys sit on it...) what can I do to figure out if I need 1.5" or 2" square tubing? And what about wall thickness?

I searched but I don't think I'm looking for the right terms, as the results I kept getting just showed me how much 1 ft of various square tube steel weighed.

Thanks for any insight that can be provided!

I recently picked up a miller syncrowave 180sd off craigslist, only 11 arc starts! Time to teach myself how to tig!

Anyways, i have a few projects coming up that I'd like to do and have been looking for some sort of formula /chart/math/etc to figure out what size tubing I'll need to use to properly support what I'm building. For example, if I know that the max weight a table will need to support will be say 500lbs (nearly 2x what it will ever actually support unless two big guys sit on it...) what can I do to figure out if I need 1.5" or 2" square tubing? And what about wall thickness?

I searched but I don't think I'm looking for the right terms, as the results I kept getting just showed me how much 1 ft of various square tube steel weighed.

Thanks for any insight that can be provided!

For something in the 500lb range, just about any standard steel tubing size is going to be enough to make a few legs out of - even .065 wall 1" tubing would handle it easily (thought it would be possible to dent it). Point is, pick what fits your budget, capability, and your cosmetic preference and go with that. Most steel structures of this type are SOOOOO overbuilt that it really doesn't matter. You will also find that the standard steel sections are cheaper...it's hard to beat 2" .125" wall square tubing when it comes to commonality.