Telescoping pipe

[stuckmotor]

I seldom have trouble finding square tubing that will telescope but the black iron pipe at Lowes won't fit into the next size up and the size above that is a very loose fit. The problem isn't an inside seam on the outside pipe. The inside diameter of the outside pipe is just too small. What do you guys do when you want round pipe that will telescope with a nice fit?

 

[RickB]

Properly sized mechanical tubing.

 

[yomax4]

Most steel houses have a chart that will assist with round, square and rectangle tubing sizing for what you want to do. Wall thickness might not all be exactly the same though.

 

[Gary Fowler]

Just do a google search for pipe dimensions. There are several charts available (one from Saginaw Steel) that list all the variables in pipe ID, OD and wall thicknesses.
Tubing will likely be easier to match up with a specimen that will fit inside of another one. Piping has a few that will, 1.5" inside a 2" comes to mind but you have to get the schedule (thickness) right for this to happen. Matching up pipe OD's to fit the ID of another one is a bit time consuming when looking at the data.

 

[BHD]

most box stores carry schedule 40 one could try schedule 80, which is thicker and could take some of the slop out of the fit,

 

[3Ts]

There is a difference between pipe and tubing. Pipe has a minimum wall thickness but is allowed to vary a little. Tubing has a much more consistent wall thickness. If you are going to telescope the tubing, you should check out DOM (drawn over mandrel) tubing. It is very consistent and you can get different sizes with different wall thicknesses.

 

[stuckmotor]

Thanks everyone. Your responses came in in a flash and gave me plenty of information to work with. I'll check what my supply house has when I'm out there. They finally got smart and put out samples. I was trying to go through Lowes because I didn't need much and the supply house won't sell less than a stick.

 

[Big Barn]

For a good telescoping fit I use DOM (drawn over mandrel) tubing which has the inside flash weld removed. Typically the inside diameter of the larger tube would be .010”larger than the outside diameter of the smaller tube for a nice sliding fit.

Here is an example of DOM tube I used for removable handles on a cart I made.





Edit: 3Ts gave same suggestion while I was typing.

 

[stuckmotor]

Nice work Big Barn. My work is crude compared to yours.

 

[bigtiller]

How much do you need? How strong do you want it?
Some ideas....
A big-stick CB base antenna is telescoping.
Some flag poles are also telescoping.