Aluminum Alloy Lug Nuts?

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The other day I installed a set of Potenza RE-11A tires on an older, low mileage, 944 Turbo. It had OEM wheels with black, aluminum alloy lug nuts. The owner said they are the original OEM lug nuts that came on the car. I've never seen a car with OEM aluminum lug nuts, which got me thinking.... I've seen alluminun "tuner" nuts for a long time but never really thought about them. The Porsche nuts were super light and seemed pretty cool, which brings me to my question. Are aftermarket aluminum lug nuts safe for daily driver road use? First thoughts are that aluminum is soft, has different expansion rates, and could have corrosion or seizing issues. That being said, if you have a summer driver which doesn't see all the different elements, would it be OK to use a set? I'd be a little concerned about them keeping their torque requirements when compared to a steel but, but then again I've never used them. Also, if Porsche was using them way back in 1986, wouldn't there have been an issue by now? I think it would be pretty cool to have a set on my car with the Enkie wheels I have, but I don't want to die either lol the set of 20 nuts had to have been at least 2 lbs lighter than the steel nuts, if not more. Anyone have any real world experience with aluminum lug nuts that they could share?
 
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I imagine the problem with them keeping their torque would be wearing against steel and causing a very small gap. This is why aluminum rims with steel lugs need to be checked after 50 miles. But aluminum against aluminum... who'd win? laugh PS, lug nuts or bolts?
 
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If they truly are aluminum, I wonder how they hold up to the monkeys with 600 ft-lb impact wrenches at Joe's Tire & Bait Shop.
 

Astro14

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Originally Posted By: strat81
If they truly are aluminum, I wonder how they hold up to the monkeys with 600 ft-lb impact wrenches at Joe's Tire & Bait Shop.
If you're bringing a high-end Porsche there...then you've got more money than sense...
 

Johnny248

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Originally Posted By: strat81
If they truly are aluminum, I wonder how they hold up to the monkeys with 600 ft-lb impact wrenches at Joe's Tire & Bait Shop.
Lol our impact guns are torque limited @ 50ft lbs
 

JHZR2

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Wouldnt the concern be the thread interface to the hub? Corrosion potential may be high, but they may also be well-coated in an anti-corrosive?
 
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One of the projects we have right now is machining custom lugnuts for the Formula Ford guys down at Sebring.It's a pass-thru ,long shank style that uses chamfered washers out of 6061,and the nuts themselves are 303. However galled up the washers are going to get,at least the washer will be sacrificial and not the wheel.
 
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Just a thumbnail version: Aluminum as a material can be made quite hard - certainly hard enough to be used where steel is normally used - and certainly hard enough to use in fasteners. I would have no reservations about using aluminum nuts and bolts. Long term? Even steel lug nuts and studs get issues over the long haul. Aluminum might have more issues, but it isn't the difference between yes and no. More the difference between good and mostly good.
 
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Aluminium has no fatigue limit, which means that used in tension, cyclic loads, it will fail at some time...every time. Nuts are slightly different in that they aren't in tension, but the threads tend to expand the nut radially...and the material will suffer in that direction. I'm not a fan of any bolted Al fasteners really...and it's not because of galling and the like, it's just a material where in certain applications there are materials with far better properties.
 
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The difference between good and mostly good makes me think of the difference between mostly dead and all dead... I would think that it's a bad idea to use aluminum (or any material prone to fatigue failure) in an application where it's subject to intense stress risers like thread roots, and doesn't receive regular inspection like, say, an aircraft would.
 
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Originally Posted By: Shannow
Aluminium has no fatigue limit, which means that used in tension, cyclic loads, it will fail at some time...every time......
I think that is true of EVERY material. There are SN curves for many materials. For steel, there is a point where the SN curve flattens out, and it appears to have no limit, but in reality, the limit is quite far out. For aluminum, the curve doesn't have that same shape.
Originally Posted By: Shannow
....Nuts are slightly different in that they aren't in tension, but the threads tend to expand the nut radially...and the material will suffer in that direction. I'm not a fan of any bolted Al fasteners really...and it's not because of galling and the like, it's just a material where in certain applications there are materials with far better properties.
I don't disagree, but aluminum wheels are quite common and there doesn't appear to be any worse fatigue issues than for steel wheels. I think this is more about designing a part for the service.
 
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Originally Posted By: CapriRacer
but aluminum wheels are quite common and there doesn't appear to be any worse fatigue issues than for steel wheels.
Same goes for Aluminium stock pots and roasting pans, but we were talking specifically fastners... When you can make an item out of an appropriate material (steel), and it adds the weight of the driver's wallet to the overall vehicle, then making them from Al (and including an inspection/replacement programme as use of such material befits) is silly on a road car, where such inspection/replacement will never likely occur.
 
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How about a hybrid lug nut like Toyota uses on their TRD forged Aluminum wheels? A rotating Aluminum collar that contacts the wheel with a steel nut that engages the bolt: Shown here mounted on the wheel: HTH
 
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I use Al nuts on my track Miata as so many other folks. I've never heard of it being an issue. We swap wheels a lot in a weekend, too. robert
 
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Originally Posted By: robertcope
I use Al nuts on my track Miata as so many other folks. I've never heard of it being an issue. We swap wheels a lot in a weekend, too. robert
It appears to me that the biggest problems with lug nuts is crossthreading and wear. Those problems occur with steel lug nuts and I suspect that aluminum lug nuts don't add additional issues to the list. Aluminum lug nuts might be a bit more prone to wear, but I don't think this is much of an issue.
 

Johnny248

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Originally Posted By: gaijinnv
How about a hybrid lug nut like Toyota uses on their TRD forged Aluminum wheels? A rotating Aluminum collar that contacts the wheel with a steel nut that engages the bolt: Shown here mounted on the wheel: HTH
This is what I have now. They are McGuard Spline Drives.
 
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