In need of telescopic steel tubing (square or rectangular)

I'm in need of a small amount of telescopic square or rectangular steel tubing (24" long outer piece and 24" long inner piece). The dimensional size
of the outer tubing is not critical, but I'm looking for something roughly 2" x 2" square. The inner piece must be able to fit entirely within the outer piece, must slide freely, yet must not be a sloppy fit.
If I were to buy A500 series structural square steel tube:
- 2" x 2" x 11 GA (0.120" wall) x 24" long (for the outer piece) - 1.75" x 1.75" x 24" long (for the inner piece)
would that work? Or will I have problems with interference from the welding seam and surface finish inside the outer tubing?
I know there are manufacturers of hitch receiver tubing and other industrial telescopic tubing, but I don't know of any supplier of small (and reasonably priced) quantities of the stuff.
Thanks, Michael
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Go to your farm supply store and look for PTO shaft tubing.
DeepDiver wrote:

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size
welding
industrial
reasonably
I've had a little luck using a round piece (pipe of the right diameter) inside a square piece when the situation allows. It eliminates some of the problems, like the seam inside the square piece, assuming it's not on center. I made adjustable trailer jacks that way, and was lucky to have the seam off center.
Harold
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Mike, Princess Auto sells telescoping steel tubing in 48" lengths. More than you want, but you can just order the stuff, and it will fit nicely (according to their catalog). You want:
2" x 2" x 0.188" 16.4lbs 1480185 $29.99CAN 1-1/2" x 1-1/2" x 0.100" 7.0lbs 1480177 $16.99CAN
These prices are in Canadian dollars. If you want to see this in their catalog, you can download http://www.princessauto.com/downloadz/DLcaller.cfm?DLS=EXT&TheFile weld-can
or you can just go to princessauto.com and order the stuff.
GWE
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I'm in California, so I suspect that buying and shipping steel tubing from Canada is not going to be the most cost-effective (or expeditious) option for me.
Does anyone know of a US supplier for this tubing?
- Michael
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Regular A500 square tubing is not uniform enough to get a good fit plus there is usually a miserable weld seam. Also, A500 is likely to be a much rougher surface finish, ask for A513 mechanical grade.
Choice one is to get the material that is made to telescope toghether. Telespar is the usual brand name to specify.
The other choice is to weld shims on the inside lip of the larger tube, outside of the smaller tube. They only need to be 1/2" or 1" wide, thickness can be ground down to get any fit you want. You will likely have one side of the inner tube shim cut away to clear the weld seam on the outer tube. Example: 2" sq x.120" wall outer tube with 1-1/2" inner tube would use .125" shims and give you about .010" clearance.
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Actually, I was looking at A513. My mistake for writing A500-series.
Can you tell me the difference between A513 and A36 tubing?
Will 2" x 2" x 3/16" A36 (outer) work with 1.5" x 1.5" A36 (inner) tubing?

That's what I've been searching for. Unfortunately, it seems that the small-batch metal suppliers (like OnlineMetals.com and MetalsDepot.com) don't seem to carry this stuff. I'm sure someone does, just haven't been able to find a supplier yet.
If anyone knows of a local supplier in the San Francisco Bay Area, please let me know.
Thanks, Michael
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snip----

I'm way behind the curve, having been out of the shop for several years now, but Jorgensen used to carry a wide variety of tubing, as did Marmon-Keystone. Check the yellow pages to see if there's one near you. My old Jorgensen stock book shows an outlet in the Oakland-San Francisco area, 1699 West grand Avenue. (415) 835-8222. It's an '88 edition, so maybe they're no longer there.
Harold
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As far as I know, there is no A36 spec for tubing. A36 just specifies a low carbon mild steel composition. Any steel supplier that tries that spec on you is saying "we have some square stuff with a hole in it that a magnet sticks to" A513 has lots of subsections Type 1 is hot rolled type 2 is cold rolled, type 5 is welded drawn (round only) A513 also has lots of specs on squareness, wall thickness, corners, twist, etc etc. So the real difference between A513 and A36 is that with A513 you have some idea of what you are getting.
Will your 2" and 1-1/2" work together? Probably. Unless you get some mill seconds, square tubing is usually some decent product. You are looking at .060" clearance per side, more than enough to clear a weld flash. You might have problems on the corners. Usually, the smaller the tube the more square the corners are. Only way to tell is try it out.
The total of .120 is going to make a fairly sloppy telescoping joint. You mentioned 24" sections, if the overlap is less than about 6" is will flop a good bit.
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Hmmm, that's the same amount of clearance in the purpose-made telescoping tubing that's sold by Princess Auto in Canada (refer to Grant Erwin's post earlier in this thread). So is all square telescopic tubing a sloppy fit by nature? I was hoping for a 3" overlap when the inner section was fully extended. (By the way, this is for making outrigger-style supports/stabilizers for a rolling machine stand I'm building. The support arms are to be withdrawn for a more compact storage footprint.)
I really can't believe this is so difficult. Surely there must be square telescopic tubing that fits together well, is commonly sold, and does not cost an arm-and-a-leg. Or am I dreaming about a perfect world again...
- Michael
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I was associated with a place that bought square and round tube by the full truckload (44,000 pounds of 3" x.120 tube is a BIG pile) When you buy like that, the material is welded up to your specs. But the mill would not guarantee tight fit telescoping.
Go back and read the response about the shims inside the tube, works well. All the boom trucks and extendable back hoes use this method. This would allow you to buy the tube you mentioned, tighten it up if required. A simple weld bead ground down will work for your low loading outriggers.
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