Size rivnut for 8mm factory holes?

Oddly, this seems to be really hard to find out! (I must be googling the wrong thing).

I have 8mm factory holes which is like to use for the wall panels. An M8 rivnut is 8.6mm outer diameter, so won't fit.
Is 10-32 correct? (I.e. These)


Well-known member
For an 8mm hole you will probably want an M5.5 according to this table

It's just one of those in-between sizes which doesn't quite work.

Easy enough to drill out to 9mm and put an M6 into it I would have thought.

Not sure where you got your figures from as they don't seem to agree with the chart. A couple of other online charts seem to be giving the same results which is why I'm questioning your figures - I'm no expert, I just remember having had a similar issue a couple of years ago and googled the figures again, so I'm quite happy to be proved wrong!
Thanks, M5.5 is probably right (I've tried M5 and M6). I measured it myself with a caliper, so it's a bit strange the table is different.

I'd rather avoid drilling, the extra effort and clean up is a bit annoying! I'm going to try and find a hardware store today with different sizes in stock (harder than it sounds) and see what I can find.


Well-known member
apologies, I was attempting to be humorous with my M5.5 comment

To the best of my knowledge no such thing exists.

I guess you could possibly go the other route and go for a smaller size rivnut and put washers with the correct diameter hole in front and behind the existing van holes (assuming you can access both sides)

If you do decide to drill, then a good tip is to place a magnet near the hole to catch the swarf as you're drilling. Saves a lot of time in clean up. And don't forget to paint the edges afterwards so they don't rust.

Eric Experience

Well-known member
There are lots of rivnut sizes, I use a lot on my builds. One variation uses external splines which works well with slightly over size holes. It is a shame that the big supermarkets control the fastener market in the states. Fasteners made in Europe are higher quality and cheaper than supermarket junk. Eric.

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