PEM nuts, or something like that for sheet metal

WobblyHand said:
To everyone, I did get the message! Ended up buying a Rivet Nut tool, plus a pile of extra rivnuts. May still play with some press fit studs, just because, sometimes you don't feel like a nut.:grin:
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That's great, you won't regret it.
Of course, before, tightwad me simply abused some 5mm pop-rivets into becoming M3 tapped.
I will also be buying the tool. :)
 
Ended up using both PEM nuts and rivnuts on the ELS motor control box. You all are right, once you have the nuts and tools, there's lots of places to use them. Used PEM nuts to flush mount the stepper motor driver and rivnuts to mount the fan guard/filters.
PXL_20221021_192037308.jpgPXL_20221021_200831792.jpg
 
Sorry to resurrect this thread, but it is relevant to the topic...
graham-xrf said:
You can get UNC or metric hank bushes, also in stainless from eBay. There are types that have serrated rivet grips, but if you make the hole a slightly tight fit, then tightening a bolt onto it secures it permanently. This would be to mount the hank nut onto sheet metal. I found using A2 stainless steel types excellent for mounting to aluminium. In thicker aluminum, I use stainless helicoils, instead of trying to tap a thread into the soft aluminium.

Steel against aluminium has that dissimilar metal corrosion potential, making a white oxide that seizes to the bolt forever. The interface between the aluminium and a hank bush becomes permanent, regardless the oxide, and the stainless threads in it will never seize up onto the bolts.
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This sounds like it would fit my use case perfectly, but to be clear, are you referring to what is also called a "rivet bush"? If so, how have you been able to find UNC versions? I've inquired with multiple hardware suppliers and have done more web searches than I can count (including eBay as you suggested) for a 6-32 version, but the only hits I've gotten are for metric threads.

The best response I've gotten for UNC is that I would have to place a bulk order from overseas - way too costly for something I haven't even tested yet.
 
foolishgrunt said:
Sorry to resurrect this thread, but it is relevant to the topic...

This sounds like it would fit my use case perfectly, but to be clear, are you referring to what is also called a "rivet bush"? If so, how have you been able to find UNC versions? I've inquired with multiple hardware suppliers and have done more web searches than I can count (including eBay as you suggested) for a 6-32 version, but the only hits I've gotten are for metric threads.

The best response I've gotten for UNC is that I would have to place a bulk order from overseas - way too costly for something I haven't even tested yet.
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20241029 Rivnuts.jpeg

https://a.co/d/8PRbRPI
 
ChazzC said:
View attachment 507571

https://a.co/d/8PRbRPI
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Those are what I would call rivet nuts, and they would work if I had more space to give on the reverse side. But I don't, so they're too deep for my needs.

The Link Filter for Newbies® won't let me post the link, but if you search the web for "Round Serrated Face Rivet Bush installation," the first result should show what I understood graham-xrf to mean by "hank bush."
 
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foolishgrunt said:
Those are what I would call rivet nuts, and they would work if I had more space to work with on the reverse side. But I don't, so they're too deep for my needs.

The Link Filter for Newbies® won't let me post the link, but if you search the web for "Round Serrated Face Rivet Bush installation," the first result should show what I understood graham-xrf to mean by "hank bush."
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Gotcha


Round Rivet Bushes Serrated Shoulder

Round Rivet Bushes provide strong reusable captivated threads in panels too thin to be conventionally tapped. They can be installed into panels as thin as 0.5mm and do not suffer from the maximum hardness or centreline to edge limitations of self-clinching nuts so are suitable for installation...
www.npfasteners.com

Did you try reaching out to Trifast USA:
Trifast USA Contact Info.png
Maybe you can get a sample pack, or at least a less-than-minimum order? I did that a couple of years ago when I wanted to try of Shear-Loc knobs without having to buy a bunch of them.
 
I did reach out to them - they were the only manufacturer I found who advertised UNC sizes on their website. Unfortunately, I didn't get a response.
 
foolishgrunt said:
I did reach out to them - they were the only manufacturer I found who advertised UNC sizes on their website. Unfortunately, I didn't get a response.
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In cases like this, I never send an email or use the website message system: I call, repeatedly if necessary. Ask @mmcmdl - I can be a real pain in the butt!
 
If only you knew a machinist that could make a few of those in the thread you need ;)
 
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