[tanshi]

no, the ones i have are 15.875mm round, i want to drill a 12.5 mm hole through the middle to take 12.5mm studs

[Bugsta]

So 15.875mm can be turned down to become 14mm or 12mm, whichever you want.

[tanshi]

OMFG!

[Zook_Fan]

What's to stop the 12.5mm thread just backing out? Thread it through and then weld it to the back of the stud? It won't be as strong as a new stud but it may hold up. Would suck if you snapped some studs and had to get home though.

[tanshi]

maybe im not explaining what im wanting to do very well.

I have original jeep wheel studs that are 1/2 inch size, they have 15.875 mm knurl.
keeping the outside 15.875 i will put them in the lathe and drill 12.5mm hole through the middle leaving only the knurl and none of the thread left.
the pic on the left below shows what i will end up with, then i will press some new long studs into this ring giving me a 12mm stud with a 15.875mm "knurl adapter" on it.

[mrw82]

Don't worry Darren, I understood what you meant (just didn't have time to reply earlier). I think it will work ok for you, at 15.875 and 12.5 you will have about 1.7mm wall thickness. I would definitely be leaving the back shoulder on the bored out stud, but how does this affect stud length of the 12mm thread, still enough for full nut engagement?
Keep the bore diameter as tight as possible to the root of the knurl going into it for the tightest possible fit. The 'adapter' will expand when the stud gets installed

When doing it press the 'adaptor' into the hub first (i'd even consider using studlock loctite on it) then press the stud in. Less risk of damage during install this way (not to mention it'll be easier to do)

[tanshi]

Thanks mark. Glad to know im not talking another language.
Good idea on the lock tite

Ill be using 3 inch long studs so plenty of length