If you want the short version of the story/problem, skip to the the last paragraph.



So awhile back I bought tanc's custom wheel spacers and rims with extended ARP studs.



After blowing out a tire on the highway because I didn't have my fenders rolled and getting towed 60 miles home (I know, I'm an idiot, I wasn't aware of the "fender rolling" process). And actually I can't even roll them all because there is a little rust starting on the rear 1/4 panel, and the guy who was helping me roll the other 3 said we better not do it because it will probably just break off. Awesome...



So it's winter time and I figured I would just put my stock rims/tires back on, and perhaps next year I'll feel like putting more money into this car and getting the rear 1/4 cut out/weld a new piece of metal in/sanded/painted...sigh. And I just got it all painted last year after a bunch of hail damage



Get the old tires on, and what do you know, they don't match up flush with the spacers. So I'm like no big deal, just take the spacers off right? Now the lug nuts won't thread all the way down. Again, no big deal, I'll just go get some open ended lug nuts? Run to NAPA, get them, and they don't fit. Can't figure out why. Assume that it's because they aren't "acorned" at the end. So I order some nice $75 BLOX aluminum light weight lugs online. Get them today, those don't fit either. I cannot figure out why for the life of me. The lug nuts I got from tanc say M12x1.50, the lugs nuts at NAPA said M12x1.50, the BLOX lug nuts say M12x1.50, I looked up the RD Tiburon studs, it says M12x1.50. I've attached pictures. Please help me find lug nuts that fit!!!!



Old lugs that work (outside)





Old lugs that work (inside thread)





New lugs that don't work (outside)





New lugs that don't work (inside thread)





Studs all





Studs close up

 

Oh jeez!! Even though the lug nuts say 12x1.5, they are not! ARP doesn't make studs long enough in a metric size. Those are 1/2-20 standard. What I did was throw on the lugnuts on a lathe and resized them considering they weren't cheap.



Just get open ended 1/2-20 from napa and problem solved. I apologize for your troubles.

 

^that



If it were me and I was really in a tight spot, I'd cut the ends off the nuts that fit, and make them into open-ended nuts until I could figure out what was going on.

 

Or take a stud/lugnut that works to a hardware store and thread it onto a test plate in the nuts & bolts aisle to see what thread pattern is.