It's common for customers or homeowners to buy tubing or pipe with the purpose of telescoping tubes or pipes. Please make an effort to read the following information ang guides. This guide will allow you to make the best telescopic tube selection for your application. Furthermore, it is going to eliminate you from losing valuable time and cash.
When selecting tubes meant for telescopic applications it is crucial to select sizes which have been just a little larger or smaller than the outside diameter or inside diameter you are planning to telescope. As a general rule of thumb, supplier usually do not guarantee that the tubes or pipes that you purchase will to put it accurately telescope. The only way to guarantee someone that the tubes that you buy will telescope is to take the tubes and physically telescope them into one another.
A common misconception is that a tube with an outside measurement of x will slide into a larger tube that has the same x measurment on the inside. It won't. As an example, a round tube that has an outside diameter (O.D.) of 1-1/2" and a 1/4" wall thickness will have an inside diameter (I.D.) of 1". Seems logical then that a piece with a 1" O.D. will slide right into it with a nice snug fit, right? It won't. You'll simply be butting 1" up against 1" and the two pieces will not telescope. In order for these two pieces to slide together you'll have to remove some stock from your 1" O.D. piece or hone out the inside of your 1" I.D. piece.
Round telescopic tubing has a multitude of walls and O.D.'s available. Typically a good pair can be found that requires little or no work to get the desired fit. Square telescopic tube and rectangular tubes are completely different stories though. The bulk of them have raised seams on the inside and they all have inside and outside corner radii that differ with each size.
Keep in mind, many service provider doesn’t have a weld on the inside of the tube because the weld flash was removed, virtually every other tube or pipe will have a weld on the inside of the telescopic tubing. This weld will prohibit you from tightly telescoping one tube into another.
The moral of the story is that there is absolutely no way to guarantee your tubes will telescope. I would highly suggest being as liberal as possible when selecting tubes that you intend to telescope and take into consideration that some type of craftsmanship may be required. This craftsmanship may be simple as sanding the outer diameter or as difficult as machining your tube on a lathe or mill.