I've had 3/8th, 7/16ths, and even 1/2 studs on race Sprites over the years.
I've run wheels with shouldered nuts like those used on American Racing
mags, and the tapered style on Minotaurs.
Never broke the 3/8ths in 15 years of racing though. Many go to 7/16ths just
because they're easier to find.
From owner-team-thicko at autox.team.net
[mailto:firstname.lastname@example.org] On Behalf Of Ron Soave
Sent: Wednesday, February 22, 2006 9:00 PM
To: Bill Dalton; Spridgets; email@example.com
Subject: RE: Lug nut material?
Good thought - I do have access to a Rockwell hardness
checker. I could check stud hardness, then choose
material. Being a Boss Mustang guy, try not to laugh
- these are Spridget 3/8 studs torqued to 40 ft-lbs (I
may go up to 7/16 finally). FYI - while I admit to run
a die over a wheel stud in a pinch, I think the
threads are rolled and really shouldn't be cut in any
way. But then again, you big-bore guys use impact
wrenches to adjust your points, so you've got more
margin than we Spridget guys do.
--- Bill Dalton <firstname.lastname@example.org> wrote:
> I would suggest something that is softer than the
> studs so that the lug nuts
> would deform first. On the Ford Mustang the threads
> are 1/2-20UNF. I used to
> torque mine to 110 ft-lbs which is the max for
> unlubricated thread and I
> would find that every winter I had to re-tap the
> nuts and I would run the
> die down the studs. I backed off 5 ft-lbs at a time
> until I found at 95
> ft-lbs I didn't have to do either. These lugnuts are
> the stock appearing
> deep acorn nuts available at good parts stores. At
> about 100 ft-lbs I didn't
> have to run the die down the studs, but above that I
> threw away about 5 of
> the 20 every winter, but never had to replace a
> stud. They were definitely a
> tougher, higher strength material than the nuts. I
> would use the 4140 unless
> it is harder than your studs.