ScottG wrote:
There are a lot of situations where you can't through-bolt.
In my case the bolt ends up in the webbing of the C channel that makes up my toungue. For most, using the self tapping screws would work fine as long as they're checked once in a while.
I ended up tapping the C channel and using grade 5 bolts - the frame is at least as thick as a bolt, more so at the webbing. Then I painted everything black and used some red touch up paint to make a mark so I can readily see if the bolt has moved.
The frame is mil steel or at least several times milder than a nut grade 5, 8, or 9.
I would if possible use grade 5 bolts that close fit the holes and hardened washers and locking nuts or preferably but more expensive and time consuming, drilled bolts and nuts, sometimes called safety bolts and nuts and safety wire. I have had the bolts in the sub frame of our tow bar come loose. They were simply replaced and torqued because I had someone else do it. If able I would do the safety wiring.
