Originally Posted by Ernie n Tara
...Looking for solid bolts now...
I just found some 2" x 1/4-20 Grade 8 bolts at Lowe's that had 1 1/8" long unthreaded shank. The square tubing is 1", so the unthreaded section is longer than the cross section of the tubing. All the 2" bolts I had previously found were about the same as the 1 1/2" long bolts with an unthreaded section about 7/8" long, so you may have to check around to find ones that have a 1 1/8" shank.
I cut about 3/8" off the 2" bolts and use 3 or 4 washers under the nut so the threads grab. Theoretically, these bolts with the longer unthreaded shank should last longer, but I don't know yet because I only recently installed several of them in our living room slide.