Use of Nut Inserts

[Cobra 29]

I want to secure a bracket with a bolt to my frame. I understand that installing nut inserts could be a solution. I have seen the different types and sizes from McMaster-Carr. Can anyone tell me the steps to install and whether the nut insert tool is needed. I found most of my info on the McMaster-Carr site page 3025. Thanks

[Roscoe]

Nutserts are ok but why don't you just drill and tap the frame?

Roscoe

[Bob Putnam]

Tapping a rail that's less than 1/8" thick ain't very strong...

You can install a nutsert without fancy tools.

Drill the hole very accurately.
Insert the rivnut.
Assemble the bolt, nut and washer as shown.
While holding the head of the bolt, tighten the nut to set the insert. A little lube on the bolt threads help.

[bkozlow]

I suggest you give Aircraft Spruce a call Tuesday at 800-831-2949.
They will send you a catalog free and they have nut insert tools for $15-20 and all sizes of inserts. I my self like rivnuts which are aluminum and have a larger shoulder on the outside of the frame. I use the 10-32 for holding clips for fuel lines, and brake lines etc. with stainless steel screws.

Bill Kozlow

[Andy Dunn]

Cool tip Bob I had never seen it done that way. Simple and makes great sense.

Cobra29, a bunch of people sell a nice starter kits (jc whitney, nutt.com). You might give it a try. It comes with the tool and assorted sizes. Check out special #6, ThreadSert Kit
http://www.nutty.com/specials.html

If you are looking at the mcmaster catalog, I find that the nut-inserts are easier to use and more consistant than rivenuts (the later might be stronger though).

Item number 95585A100 is the tool hat comes in the variety packs and works fairly well.


Andy

[Cobra 29]

I read names such as rivenuts, nut inserts and others. What are the differences and which should I use to attach a 1/4 20 thread to my frame? I like the idea of using a rivit type tool to install due to the lack of space around the attachment point.

[Bob Putnam]

Rivnut is just a brand name (what's the code for trademark anyway ) for the generic threaded insert.

There's a fair amount of strength difference between designs, especially resistance to turning and pullout. If you are going to use a 1/4" thread, the cheapo installation kits are marginal and the bolt/nut method above may be your best bet - especially if you're going to use a steel insert. Steel would be my preference for anything beyond 10 lbs per insert, or something that will removed and replaced more than once.

You can get a good idea of the selection from the McMaster Carr catalog (search on "nut insert").

[Andy Dunn]

one other thing to note is that a 1/4 threaded insert, requires a 3/8" hole. The holes are big compared to the end bolt size. One of the coolest uses for thread serts that I have seen, is the Crane Roller Lifter Retro Kit. They use two inserts in the block drain holes to mount the roller guide.

http://www.trickflow.com/articles/st...ss2_image1.htm

http://www.trickflow.com/articles/st...ss2_image2.htm

http://www.trickflow.com/articles/st...ss2_image4.htm

http://www.trickflow.com/articles/st...ss2_image5.htm

[OhBuoy]

I like that diagram. I was meaning to put something up for people who have not used these before, because I got hit up for $10 for a zip lock bag with an Allen Wrench, A threaded rod connector and a long allen head screw. Works similar to what you showed except you turn the screw head and hold the threaded rod steady.

-Tom

[Jack21]

For attaching stuff to the frame up to about a size 10 or 12, I use self tapping screws, a nutdriver tool, and a drill. They don't come loose. A little wheelbearing grease helps lube the tapping, and protects the hole in the frame from rusting.

1/4" or larger, I use the drill & tap method. But the drilled piece is usually thick enough to hold the threads.

I'm happy to see that there are lots of folks out there that know their way around a McMaster-Carr catalog. Next to Summit, that's my most frequently used catalog/website.

[Steve Siedlecki]

Could I use one of these inserts in the fiberglass
ribbed portion of the trunk liner to hold a bracket for gas lift. Would it be strong enough ?
Or do I have to cut through the glass and glass in a piece of steel and then tap?
Thanks,
Steve

[lippy]

Originally Posted by Bob Putnam

Tapping a rail that's less than 1/8" thick ain't very strong...

You can install a nutsert without fancy tools.

Drill the hole very accurately.
Insert the rivnut.
Assemble the bolt, nut and washer as shown.
While holding the head of the bolt, tighten the nut to set the insert. A little lube on the bolt threads help.

I received my order of Pemnuts and Rivnuts earlier today and was fooling around with them on a piece of scrap metal. Pemnuts worked well, but I had easy access to both sides of the workpiece. But when I tried the Rivnuts using this method, the head of the bolt would just break off. I drilled the hole using the correct bit and a press, so it's clean and accurate. I used 10-32 stainless nuts and bolts, lube, and a plain steel Rivnut. Anyone tried this method successfully and have any idea what I did wrong?

[strictlypersonl]

Stainless steel screws are generally not as strong as other grades. In your case, I would use a standard black-oxide Allen screw for the installation. Guaranteed Grade 8.
McMaster-Carr

[Rick Parker]

This is an old thread, however it brought to mind that some of the "Bubble packs" that are prepackaged in hardware stores have the small installation tools included. A grade 8 socket head cap screw, a hex shaped coller with a serated tip to prevent the insert from spinning while installing. This saves the need for purchasing expensive toools and still gives a good result. Most frame rails are a minimum of .120 wall and will accept a tapped 10-32 screw for securing fuel lines etc without the need for Rivnuts.

[lippy]

Originally Posted by Bob Putnam

Tapping a rail that's less than 1/8" thick ain't very strong...

You can install a nutsert without fancy tools.

Drill the hole very accurately.
Insert the rivnut.
Assemble the bolt, nut and washer as shown.
While holding the head of the bolt, tighten the nut to set the insert. A little lube on the bolt threads help.

Here is an update. First, I was able to get the Rivnuts to work with the cap screws Bob recommended. At first, the Rivnut would sometimes turn in its hole. So I took a recommendation I found elsewhere on the web and took a short, stiff section of angle iron about 6" long and drilled a hole near the end just large enough for the screw to fit through. I then inserted the angle iron in between the Rivnut and washer in the diagram above, and held the angle iron from rotating, which prevented the Rivnut from turning. It's important to use the smallest hole possible in the angle iron so the Rivnut does not become distorted by pulling up against a larger hole.

As mentioned in a prior thread, the Pemnuts are sort of slick because they look clean and don't have a shoulder that sits above the sheet metal in which they are installed. The problem is that they are easy to install using a hammer in an unattached piece of sheet metal, but they are difficult to install in tight places. For that reason, I tried to install a Pemnut the same way as the Rivnut, using the tool above (with the angle iron) to squeeze it into the piece of sheet metal. It seems like it worked fine. This may be the ticket.