Rivnuts

[Tigercubrider]

You can buy an expensive tool but it's easy for diy to use a bolt that fits the rivnut, a couple of washers then a larger studding coupler nut than the thread of the rivnut, and another couple of washers.

Assemble in that order, spin on the rivnut and insert into hole.
Use a spanner to hold the coupler nut against your surface and (ideally) use an impact driver to wind in the original bolt while stopping the coupler from moving. It can be done with two spanners but kinda needs three hands.

 

[Tigercubrider]

You can buy an expensive tool but it's easy for diy to use a bolt that fits the rivnut, a couple of washers then a larger studding coupler nut than the thread of the rivnut, and another couple of washers.

Assemble in that order, spin on the rivnut and insert into hole.
Use a spanner to hold the coupler nut against your surface and (ideally) use an impact driver to wind in the original bolt while stopping the coupler from moving. It can be done with two spanners but kinda needs three hands.

 

[Harry Bloomfield]

So do they slacken off again when the bolt is undone?

Unless they have been damaged, the rubber regains its shape as the bolt is released and the can be pulled back out, though not after they have been in a while.

 

[mattylad]

I used rivnuts a lot, M3-M6 and yes they need a few mm spare behind them.
ISTR the tool is about £19.

IF not tight enough also over time - they can become loose and just turn when trying to undo them, hence I will not use them for earthing.

 

[Harry Bloomfield]

I used rivnuts a lot, M3-M6 and yes they need a few mm spare behind them.
ISTR the tool is about £19.

IF not tight enough also over time - they can become loose and just turn when trying to undo them, hence I will not use them for earthing.

I once put a very expensive 3K3 control panel in, with many cover panels held in place by 6mm bolts and captive rivnuts inserted in the main body. Every single one of the rivnuts hadn't been properly installed by the manufacture and would push out.

 

[oldbutnotdead]

I might have borrowed one of those RS kits from a previous employer, it has been very handy. Yes about 10mm clearance inside for the nut bit, yes the head projects slightly from the surface so you don't get a flush fit.

 

[Keithmac]

Yes thanks, I have seen that but being a skin flint I found a cheaper and whaT looks like a very inferior version on Ebay: https://www.ebay.co.uk/itm/143908646068?_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=233198&meid=1e07b554d13c4da781603d71f7ed9de6&pid=101195&rk=6&rkt=12&sd=154564300037&itm=143908646068&pmt=1&noa=0&pg=2047675&algv=SimplAMLv9PairwiseWithPLXWeb&brand=Unbranded&_trksid=p2047675.c101195.m1851&amdata=cksum:1439086460681e07b554d13c4da781603d71f7ed9de6|enc:AQAGAAABEKUNF6c4uK8jf11JWTr87loJx88tfUsXN%2BdGMcnz4EaSyCA4gPOOTft5TwkvzmIMiT9PsDICrFpndOnMYh080pL%2F7m3y8T2LWXGW0IOC9Sf%2Fc51y49bdrsVsgEYmeSlA1Dfs2ri67lWzvt401O2Iu7MC7Duoed%2BhlP1tuQ8KfLkId%2BcLRZouI1AoghQzK4gjx43H59E7QolFMGtZOO5%2F7UKXcDGME5cB0vgmdk0v55GJpqo2vRxFkMSISQAYKQwN5%2BYAlQUMao7rBvgtlYG0TJEJNX%2BhQCGD3cb5a1axQw%2BDEaA2z3FdlWVR%2BbPxH%2FzOVhKEy3UR93H6p%2BFdmsn6seeEtKQC6P9XQ8bUPckhsWV8|ampidL_CLK|clp:2047675
Potentially I'm looking at doing 16 inserts for this particular project and having never 'needed' them before I'm a bit reluctant to spend too much.

I have onecof those tools, works fine for M5 up to M8 rivenuts.

A properly pressed rivenut is an excellent fitting.

I dab a bit of threadlock on the back side of the flange for belt and braces.

 

[Keithmac]

these rubber things are also described as Rivnuts or rubnuts. Used in hollow aluminium sections exposed to wet, dirt and salt. Might be intended to avoid the galvanic corrosion when steel and aluminium meet.

View attachment 242080

I have considered using them in a garden wall to hold a gate bar, with the idea that the rubber will absorb vibration.

We call those Wellnuts, used on motorcycle fairings (especially Honda's). They are a real swine when the insert has correded onto the steel fairing fastener, had a few battles over the years!.

 

[SUNRAY]

I love this site for the brilliant help offered.
Cinch nuts: Brilliant devices, I have used them for larger devices in panels, like main isolator and big transformers but historically I've found they become loose with repeated unscrewing and also require decent access to the rear of the panel.
Jack nuts: I've used a fair few (we used to call them spiders). exactly like plasterboard intersets again found they tend to become loose with repeated use, also require a lot of space behind the panel.
Of course others have commented that Rivnuts can move too... Threadlock: Lovely tip thanks.
Rubber types: I have a unit which is basically a lightweight aluminium 25mm square tube. I've been looking for a better way for the fixings without distorting, this looks like it's worth trying.

My first panel experience was all M4 trilobal self threading screws, when I was able to choose my own I moved up to mostly M5 as the slots in DIN railare a bit big for an M4 head then on to big head Ph2 self tappers

I might have borrowed one of those RS kits from a previous employer.

Again thanks for the help.. it looks like it'll cost £3-4 for the fitting I'll require so I think it makes sense go to the £10 kit from Ebay.

 

[SimonH2]

Yeah, rivnuts are brilliant for making threaded fixings into thin sheet. I've used a few myself and thanks to buying a kit from someone who was retiring, have a tool for doing them (if you were local I'd offer to lend it to you). As mentioned, for one or two, just use a bolt, washer and nut - but doing it that way it's easy to get them skewed.
But they do have to be done 'kin tight into the panel or they tend to turn which is "a bit annoying" At my last job, one of our clients made electrical panels, and as they used punch tools and/or laser cutters, they used the hexagonal nuts and cut hexagonal holes for them - that gives a good fit where the nuts can't turn. They also used something akin to a battery drill to pull them up.

 

[mattylad]

I have the tool, it was in my toolbox when I left a previous employer. (oops)
I had 2, one for M4 and one for M5 (used them daily so easier to have 1 per size used) both with spare mandrels for other sizes in seperate bags.

Unfortunately it had an M4 mandrel in the one in the toolbox and I handed back the spare mandrel kit with the M5 mandrel in - my most useful size

 

[Tigercubrider]

An alternative is to punch square holes and use caged nuts