Parker Steel, Toledo, Ohio, now offers square carbon steel telescopic tubing. Telescopic tubing is a precise tube that provides better tolerances than standard square tubing. The tighter tolerance allows another tube or another solid shape to slide inside the tube without any problems. Generally with standard square tubing, a combination of the weld bead and the tolerance won't allow tubes or shapes to slide inside the tube. The tolerance on a standard square tube is ± 0.3. However, with telescopic tubing, the weld bead is removed, which allows a tighter tolerance inside the tube.