"Lug studs are 1/2-13"- - - - - - -what sort of oddball vehicle do you drive? All the 1/2" lug studs I've ever seen are 1/2-20. Lots of OEM wheels are hub-centric AND use tapered lug nuts. Some of the oddball aftermarket wheels I've seen use huge center holes so the studs support the vehicle weight, but that's not the best idea in the world.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!