I am designing a chair that has an adjustable length. I want to have 1/4" steel pins that go through a hole in a bracket, through a 2x4, and come out to go through a hole in the other side of the bracket.
I want to install metal tubes in the 2x4 to prevent fretting; I want non-threaded inserts long enough to go through a 2x4 (I'm not sure which direction yet). I cannot even find a name for this hardware, let alone a vendor.
Any information is welcome