Slot nuts?

Can anyone explain (maybe some photos) how slot nuts are supposed to work? Do the bolts screw in toward the bed rail, or out from the bed rail? If the bolts are screwed in toward the rail, don't they bottom out and damage the rail? How are things attached to the slot nuts? I should probably just order some from Amazon and play with them, but would like to have an idea of what else I need before buying more stuff I won't use.

I am trying to make a frame assembled from bar stock (e.g. angle iron) and attached to the bed rails. The idea is to mount a tool box on the frame without having to drill through the truck bed. Box will sit on the bed floor and would be bolted to the bottom of the frame.

 

The bolt you use should pass through whatever frame you’re bolting to the bed but not through the slot nut. Just like using unistrut or slot nuts on a milling table; the threads of the bolt should engage the threads of the slot nut but not protrude through the the nut.

Also, by definition, bar stock is not angle iron.

 

Still not completely getting it. What keeps the slot nut from sliding around in the track if there's no inward or outward pressure from the bolt?

 

I'm thinking of these things. They stay in place because you exert outward pressure by the nut against the outer edge of the track when you tighten the bolt. You're basically clamping the outer edge of the track bewteen the flat nut inside the track and the bottom of the attachment. No way to do that with track nuts?

 

This is what I mean by track nuts, and an application that doesn't make sense to me in the second photo. Don't they slide around in the track? Maybe they need a washer or spacer to let the bolt pull them outward when tightened?

 

Maybe this will help you. If you zoom in, you’ll see a bolt going through the bed bar bracket into something in the track. Hint, it’s a t-nut.

 

I know exactly what you’re talking about. I use them as a machinist and the concept is also used in unistrut, as I stated above.

https://youtu.be/ZZdtZaoWm44

This guy installs unistrut in his bed and discusses the concept. Hope it helps.

 

Hm, cone nuts, another variation. So the rails on the Tacoma/Tundra are basically a smaller version of unistrut.

 

You need something on the outside to pinch the track in the middle.

This guy has made his own T-nuts to work with a mountain bike wheel holder.

https://www.tacomaworld.com/threads/mtb-wheel-hauler-contest-name-this-thing.711725/

 

Actually what I meant was 1" aluminum square tube as it's called at Lowes. Another possibility under consideration is some of the various profiles of aluminum used for screen porch frames.

If there are any existing designs I should look at about this approach (bottom-mount box mounted on a steel or aluminum frame that's mounted to the rails) I would appriciate any links. Main goal is to avoid drilling through the truck bed, primarily because of the hassle involved in removing and remounting the box.