Nominal clearance needed to telescope square tube

What should the wall thickness of 3”square tube be in order to slip/ telescope 2&1/2” tube into it -providing weld seam removed? Planning to make legs for a table that are adjustable. Don’t know if can slip 1/4” wall or need to reduce to 3/16”. Appreciate any input.
Thanks

Welcome Bryan, With telescoping the welded tubing, always take into consideration the internal weld seam of the larger, external tube

3/16 wall 3” slips over 1/4 wall 2 1/2. It will have a little wiggle room.