Rivet nuts??

Ducky's Dad

Explorer
You have a pic? Sounds interesting. Thanks!
Just finished up the other side last night, so I'll try to get some pics this weekend. Driver's side wasn't bent, but I decided to do a preemptive reinforcement while I had all the tools and parts out.
 

Ducky's Dad

Explorer
You have a pic?

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First two pics show the standard N-Fab pinch weld mounting. Per their instructions, the only things supporting the steps are six bolts each side, through the pinch welds. I substituted 3/8" stainless bolts for the supplied hardware. Third pic shows the rivnuts/nutserts installed into the box section of the rockers, taken from under the truck. These are heavy duty, cad plated, knurled steel serts using a 25/64" hole. Fourth pic shows the reinstalled N-Fab steps, with 1/4"x20 Grade 8 cap screws into the rivnuts, with anti-seize on the threads because they will have to come out sometime. I added short compression sleeves behind the steel plates where the recesses are formed into the rocker. Sleeves are just a large I.D. nut of appropriate thickness, with the 1/4"x20 slipped loosely through that nut.

The standard N-Fab mount is fine as long as the only load applied to the steps is the weight of drivers and passengers getting into/out of the truck, because their steel plates rotate in slightly to bear against the inside of the rockers when downforce is applied to the steps. But, if you apply an upward load from under the steps (like getting stuck in deep sand or hitting a stump or rock with the step), the whole step assembly tends to move up and that rotates the steel plate away from the inside of the rocker, and that's how I had bent my pinch welds. The 1/4"x20 bolts hold the plate flush against the rocker to eliminate rotation and keep the pinch weld from bending. I used 14"x20 because those were the biggest steel rivnuts I could find, and I used Grade 8 because the bolts are in both tension and shear and G-8 is a lot stronger than stainless. Rivnut placement is not scientific, but is a function of where I could actually fit my drill and nutsetter. Installation is now noticeably more rigid when stepping into and out of the truck. Steel brackets are shiny because I cleaned them up and shot with engine enamel while they were off the truck. The N-Fabs were/are full of rust, especially inside the main tube, so they probably won't last as long as the truck does. Called N-Fab and they told me that the tube interiors are not coated with anything and that their warranty applies only to the outside powdercoating
 
Last edited:

Kgorman

Observer
A couple quick questions about using nutserts:

- do you match the material being drilled with the nutsert? Aka use steel for steel?
- how does one protect the hole from corrosion? Assuming drilling steel/vehicle body.

TIA
 

Kgorman

Observer
A couple quick questions about using nutserts:

- do you match the material being drilled with the nutsert? Aka use steel for steel?
- how does one protect the hole from corrosion? Assuming drilling steel/vehicle body.

TIA
 

Ducky's Dad

Explorer
you dont have to. I use steel in everything
You can get away with mix/match, but it's a good idea to use anti-seize with dissimilar metals. And always use anti-seize with stainless because it has a tendency toward galling when torqued. Your installation will be about as strong as the weakest link, so use aluminum in lower stress situations. Stainless is not as strong as Grade 8, but will last longer in most situations.

put RTV/Epoxy/sealant of some sort to coat everything. called wet installation
I ALWAYS paint the raw edges of the holes after I drill them, and the I put a dab of RTV silicone to seal the deal.
 

freshlikesushi

Free Candy
with rtv or whatever its not required to

Just saying...if you put it into a channel, do you coat the inside of the channel to? that's gonna rust before the edge will.....
 

Ducky's Dad

Explorer
with rtv or whatever its not required to
Belt and suspenders approach. Not required, but better is still better. I try to not cut any corners, and five minutes with a small paintbrush is worth it to me.
 

freshlikesushi

Free Candy
Yeah, but that's like putting a square of rain coat over your head in a downpour. If you aren't coating everything under it, then there is zero benefit. RTV or some other type of sealant will protect as better (if not better) than your paint. In the aerospace industry when we make a repair, we use an RTV type derivative to insulate the rivets and install it. Stops corrosion and seals everything nice and tight.
 

mtbxj87

Adventurer
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I installed a few rivnuts the other day. I tried a few methods before I realized the nutserts I bought where the same thread as my power steering puller installer. Worked like it was made to do the job
 

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