# Forum Home Renovation Metalwork & Welding  What size/thickness square tube?

## Cuppa

Ive had this bright idea to convert an old steel framed desk to a mobile worktop by adding some wheels to it. I also want to raise its height to the same as my drop saw, so I can use it as a work support. The easiest way to do this will be (I think) to weld a sub frame to which the wheels will attach & which will slide onto the desk legs. The legs on the desk are 25mm x25mm externally. What Im hoping someone can tell me is what (If any) size tube with slip nicely over the legs.

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## PlatypusGardens

Probably won't be easy finding something that's a snug fit.
I've found most tubing etc is a few mill off int/ext. 
In times like these it's usually best to take a piece down to your local steel shop and see what they've got. 
But might be a bit hard in this case unless you cut the same amount off all 4 legs...   
Another way might be to make the sub frame with pins rather than sleeves, and poke the pins inside the table legs.
Or round tubing.... 
Or cut the legs off and make a new frame and legs...    :Smilie:

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## ErrolFlynn

http://www.orrconsteel.com.au/austra...ural-steel/CHS 
You'd have to figure out how to lock things up for a stable bench.  It might be worth considering some sort of scissor lift design.

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## ringtail

30-30x2 will give you 1 mm of clearance which is fine for a workbench. Just push it over to one side and weld it out. You could go 30x2.5 and give the 25 mm a light hit with a flap disc until it fits snug.

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## Cuppa

Thanks all. Appreciate all the suggestions.  
Cuppa

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## Marc

30x30x2 over 25x25x? ... snug fit ... take a ball peen hammer and ding all 4 sides of the 30x30 slightly on the edge and also 50 mm away from the edge. Drill a 6mm hole in one of the lower dings.
Hammer it in position and plug weld both together through the hole.

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