About nut inserts (which kind is best)?

[graham-xrf]

They are called different things..
Hank bush? Rivet nut? Nut insert?
There seem to be fundamentally two kinds, and the serrated hank nut, possibly known as "nutsert", seems to be the most widely known. I now have need to use some on a car necessary brake plate shield modification. If I do have to buy a insert tool, I would hope to find it useful again in the future, and I don't want to end up with junk.

I have already made one mistake in buying some M6 nuts that are unwisely chosen (too big), and appear to need some kind of swage tool to mount them. Maybe, all they need might be to simply put them into the sheet metal hole and do up the bolt until it crushes the little flange? Perhaps I should mention that the nut I intend is made of stainless steel A2 (aka 304)

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The other sort seems to come in a great variety of types, like "countersunk" and "reduced head". There are also all kinds of insertion tool types ranging from "pop-rivet" style through larger, longer handle versions, and various gadgets that are driven from a cordless drill.

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One of the "driven" kind has a side handle, presumably to stop rotation.
The king of the heap (from eBay) is the red gadget kit at £40. With no side handle, it looks like one just grips it with one hand while working the cordless drill driver with the other.



I can appreciate the drill-driven types might make the job easier, but the first simple hand squeeze type looks able to get into a space where all the others could not.

I have never used these before, and I would appreciate any tips the folk here might have, especially if some kinds, in your experiences, are just a waste of money!

 

[Jim F]

I have used both hand types, with mixed results.
The powered unit I used was a dedicated air driven tool that worked excellent.

 

[Winegrower]

The rivet nut is widely used in aviation for blind nut installation. It works fine. If you only have need for a few nuts, you can use a screw with a nut on it, and run the nut down to the end, pulling and upsetting the rivet nut. A few washers reduces torque on the screw and protects the surface finish.

 

[WobblyHand]

What you call hank nut #3 is used for sheet metal. You use the tool rivnut tool 1a to collapse the nut and grab the sheet metal. They work ok. It is a bit of an art to get the pressure correct, even with the quality ones. Hank nut #3 won't ever come out, which can be both good and bad. I used that style nut to mount some items in an aluminum box. There's another style called a PEM nut which has a profile on one side, the other side is flush. You typically press the PEM nut in place. Both have their uses. For my ELS power/stepper driver box I ended up using both PEM's and hank nuts. Pardon the untidiness, but that's how it goes sometimes. Unfortunately, you can't see them in the photo.

 

[darkzero]

I use the type in your second pic, I refer to them as rivnuts. They work well when used properly as do the installation tools I have.

You don't need the tool to install them. You can just use a screw & a nut. But if you're gonna install more than just a few I'd recommend getting the tool.

I've got 2, larger one is easier to use, smaller one fits in tighter areas. The ones I choose both use the same style mandrel. Larger one came with a larger mandrel that the smaller one ddidn't come with & the smaller one came with smaller mandrels that the larger one didn't come with. These mandrels are sold separately too of course.

I don't like the style of tool like the 1st one you listed with the blue handles. Maybe they're a copy of some other name brand but all the ones I've seen were very poor quality & they break easily.

 

[OTmachine]

I like this style tool, but they are out of stock. Apparently, you slide the blocks to adjust. Saw a youtube video someplace and thought that it looked promising.

 

[Mill Lee farm]

I like rivnuts. They do sit about 1/16” proud on the “flush” side so keep that in mind for your application. In other words, if you just drill a hole in your brake backing plate, install the rivnut and bolt it on, your backing plate will actually have about 1/16” gap


if that is ok then you’re good to go.

You can definitely install them with a simple bolt, nut and some washers (to reduce friction)

Otherwise I can also attest to the Astro Pneumatic tool pictured above. It’s what I bought and I’m very happy with it.

Astro Pneumatic Tool 1442 13" Hand Rivet Nut Setter Kit - Metric & SAE W/ 60pc Rivnuts https://a.co/d/9bEnWtR

 

[Advil]

If you need serious strength and mounting quality, you can also use:
Two lug all metal anchor nuts
which are frequently also referred to as a "rivnut" as they are held in place by a rivet on each side.
They also have miniature that have narrower rivet spacing on each side but are slightly harder to install because of this.
Used tons of these building high performance aircraft and some in kit cars. If you get the rivets in right, they hold for the long term. And if one stops holding or you mess up the install, you can carefully drill the rivets out and redo it. They're not fast to install, but they are reliable.

Also if you take your time and counter sink your rivets, they are completely flush on the outside of the panel.

 

[markba633csi]

Pem nuts are seriously strong- and flush on one side
I don't remember what it takes to install them- we always farmed it out

 

[projectnut]

I have used the second style which McMaster refers to as rivnuts on our motorhome. The motorhome has several side panels that are hinged at the top and provide access to things like black & grey water tanks, water heater, and other mechanical components that may need occasional service. The panels originally had sheet metal screws on the bottom to keep them in place.

We drain the water heater and the freshwater system after each outing. It was obvious that removing and replacing the sheet metal screws on a regular basis would strip out the holes in short order. To address the potential problem, I purchased a few packages of 1/4-20 rivnuts from McMaster. Over time as I access each compartment, I drill a larger hole and insert a stainless rivnut to make future access easier and eliminate the potential that the original screws will strip out.

Knowing I would be doing a couple dozen over time and in many cases, there would be limited access I also purchased the proper size wrench driven rivnut tool. It's a little more difficult to use than the larger air driven or lever style tool but can get into places where neither of the other styles can.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

The first nuts installed in the water heater door frame have been in place 10 years. The door is opened and closed a dozen or more times a year and the rivnuts continue to work just fine.