Wheel Stud Thread Length when using spacers?

[Benengo]

I'm trying to work out if i need to get longer studs when using 10mm wheel spacers. Looks like there is enough thread remaining with the added spacers but there must be a recommended industry standard for the length (depth) of thread for a M12 wheel stud (bolt)?

TIA

[996Keef]

1.5x the stud diameter so 18mm is what it most likely has as standard

In reality 8 threads would do it.

10mm spacers are tricky, not really deep enough for the centrebore to be retained, make sure you use hubcentric ones, I think the thinnest I've seen is 12mm and those aren't brilliant, bit thin around the bore.

[Mave]

FWIW we always require at least 1.5 threads protruding through a nut once the joint is assembled, so it might be worth doing a visual check to make sure it's long enough whichever way you go.

[InitialDave]

Thread engagement of 1-1.5 times the thread diameter is a pretty good rule of thumb.

Are you just wanting to use spacers, or are the spacers part of other changes, like fitting different wheels?

I helped a friend put aftermarket wheels on his GR Yaris, and even without having to use spacers for brake clearance, we'd probably have needed to change the studs due to the difference in things like the nut seat.

[QBee]

I have used 6mm spacers on my TVR to make Ford fit wheels (the car has Sierra hubs) sit in the correct position - most are too far into the wheelarch.
I have found these to be fine - no wheels have fallen off in 40,000 miles. I have about 8 full turns on the wheel nuts. I wouldn't risk running 10 mm spacers on my car - too little thread in the nut. Longer studs are easily available in decent car spares shops.

[stevieturbo]

In some areas of motorsport, they insist that the threads of the stud, must be visible beyond the nut itself.

Obviously this makes sense, and for scrutineering helps too.

For wheel bolts, very unpractical though. Or those who use closed end wheel nuts.