[Mk2] [Generic] Wheel nut thread engagement

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tiff_lee
Posts: 384
Joined: Thu Jun 04, 2015 2:18 pm

[Mk2] [Generic] Wheel nut thread engagement

Post by tiff_lee »

What's considered the minimum (safe) amount of thread engagement on wheel nuts?

I'm running Skyline R32 GTST wheels on the front and GTR on the rear and this gives me about 15mm of thread engagement which doesn't seem a great deal.
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Generic] Wheel nut thread engagement

Post by C35Rob »

On steels of comparable strength there should be thread engagement of at least the diameter of the stud for stud and nut fasteners. I.e an M12 stud should have at least 12mm of thread engagement.

The MSA call for 1.5x the stud diameter for wheel nuts, so a 12mm stud would need 18mm of thread engagement on the nut. In reality 15mm is totally fine as long as they're correctly torqued and not Ali nuts or whatever.
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
SonicSW20
Posts: 3681
Joined: Mon Nov 29, 2010 7:54 pm

Re: [Mk2] [Generic] Wheel nut thread engagement

Post by SonicSW20 »

Above is sensible. You can work out how many turns this is as we know the thread pitch. 1.5mm thread pitch, so 12mm / 1.5mm = 8 turns, or 12 turns if we use the MSA spec.

I'd take the turns as the amount required to get "finger tight" to be on the safe side.
tiff_lee
Posts: 384
Joined: Thu Jun 04, 2015 2:18 pm

Re: [Mk2] [Generic] Wheel nut thread engagement

Post by tiff_lee »

Hey Rob thought you had moved on mate! must be cat B by now ><

It's only just about 9 turns, i'm just about to order some steel nuts for it as it had aluminium ones on (ebay is absolutely flooded with them). I don't recall reading anyone fitting longer studs when using R32 wheels although that doesn't mean to say it's ok.
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Generic] Wheel nut thread engagement

Post by C35Rob »

@lee, yeah mate, been cat B for a while now, still hating it 😂. Mr2 is long gone but I still drop in now and again.

The only extended studs that fit properly are the arp ones (arp 100-7715), I've installed a couple of sets. I had a really nice set of black open ended RAYS chromoly steel nuts too, expensive but worth it imho
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
timmomr2
Posts: 305
Joined: Sun Oct 11, 2009 11:35 am

Re: [Mk2] [Generic] Wheel nut thread engagement

Post by timmomr2 »

I have these wheels on my car and have the extended ARP studs as I also have 10mm spacers on to make them fit a little nicer. The studs were away enough to fit and not expensive I think it's worth the work to have a little more thread available but there is no science behind my opinion :)

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