I need to secure two 3/8 bolts to hold a bracket in place. I cannot gain access to both sides only the outside. One bolt will have 2 inches of exposed thread and the other three inches of exposed thread. The bracket needs to hold between 50 and 75 lbs. What fastener would you suggest.
I found this place with a bunch of ideas and possibilities.
http://www.hansonrivet.com/index.php4 (http://www.hansonrivet.com/index.php4)
Let me know what you have tried.
Thanks
Grant
Can you tap (thread) the hole? Then you would just run your bolt into that....
Whatcha think?
God bless,
John
I could but I am not sure there is enough thickness to get many threads? We are talking maybe .25 of material.
Grant
Grant,
Can you weld or Helli-arc 2 nuts on to what ever surface you have or is it to thin material.
Can you drill a hole and push through a commercial type large wing nut. Hilti has those down on Power Inn road. I used the poly ones to hang wall frames to ceilings in commercial buildings. Just some Ideas
Dave
A friend just showed me those fasteners but we have the complication of the material being the HAT channel type. This makes it difficult to get the wing in place and not pull against the lighter material.
Keep the ideas coming. Welding is my least favorite option as material behind could smolder and burn the bus down!!!!
Grant
I have used these type from the catalog you posted and they work great.....HTH....Tim
http://www.hansonrivet.com/w71.htm (http://www.hansonrivet.com/w71.htm)
I don't understand the "2 inches of exposed thread and the other three inches of exposed thread." Typical SAE bolts only have 2D + 1/4" of thread length, on a 3/8" bolt that is 1" of thread. If your application requires a longer thread than that, you may need to look at all-thread rod or a specialty bolt.
You also don't say what you are fastening in to. If it's sheet metal of some sort, thinnish, then I would use a rivnut. If it's thick, some other sort of expanding internal threaded gizmo, like a drywall expansion fastener. If you decide to use a Rivnut, don't buy the installation tool, I can tell you how to install them with a bolt, a piece of steel and a nut. Also, 3/8" is probably overkill, probably a 1/4" rivnut and bolt would work fine for under 100 lbs of shelf. The rivnuts probably come in different lengths for different thicknesses of material. I use rivnuts all the time on my race cars, to attach various bits and bobs. If you had access to the back, a aircraft nut plate would be better, but you don't have access.
Brian
I am trying to install a bracket that will hold on section of an awning on the side of the bus. Unless I can get all the way to the bottom of the middle sectio of HAT channel, I will be using only the section of overlap of the roof skins. The bolt length is so I can secure the bracket given the curve of the roof.
Thanks
Grant
In that case, particularly if you can get the rivnut into a piece of the roof support structure, I think the 3/8" rivnuts would be a good choice, or a blind hole rubber nut insert per the link below, which would give more sealing perhaps. In either case using a little non-setting pipe dope on the threads will help keep moisture out of the roof as well. The Rivnut, if installed properly in a well fitted hole, will be watertight as well, permanently installed while the rubber nut inserts are not permanent (they only clinch up when the bolt is tight, when it is loose they can be removed from the hole), and the rivnuts are stronger than the rubber insert nuts. If going through the roof and a typical top hat section, you probably need a grip length around .25" or so, but they come in fairly wide ranges.
I use well-nuts - the rubber insert nuts - to fasten things on the race car that I want to come off in a crash, like the dashboard if my driver's knees can come up and hit it. They tear out with sufficient force, but not too little a force, kind of a mechanical fuse if you will.
Here is how to install rivnuts without a factory tool. You don't need to use scuzzy rusty old junk to make the tool like this guy did. but the process works a treat. http://www.fjr1300.info/howto/rivnut-tool.html (http://www.fjr1300.info/howto/rivnut-tool.html)
Brian
Make a bracket that will extend beyond the area you can't get to, and attach your awning bracket to that one.
Not only will this let you get the holes where you can work with them, it will distribute the stress over a larger area.