Aluminum Lug Nuts - Thoughts?

AxeHealey said:

 for the threads to get screwy. 

03Panther said:

I had never heard of aluminum lug nuts, before the Bentley thread with its dull golden colored lug nuts!

I've personally never seen or heard of a lug nut problem that was actually caused by anti-seize, and not a different problem, blamed on lube (yes, it changes torque spec, but that's easy) 

So, I may not be the best source. That being said, I would NEVER consider using dissimilar metals without anti seize. 
I wouldn't have imagined aluminum nuts was a good plan, but trust the info presented, so with the right alloy, guess so!

In my case, the ARP studs are steel the lug nuts were aluminum, so the anti-seize was there to prevent any chance of corrosion between the differing metals. 

I also slap just a touch of anti-seize on the mounting face of the wheel for the same reason. 

Back in the air-cooled days Porsche used magnesium lug nuts.  They are ridiculously light.  They are replaced with steel lugs for racing.  PCA ruleset requires that but I don't know the rationale.  Remember, VW and then Porsche used a lot of magnesium to reduce weight, like crank cases up to and including the 2.7 liter sixes.

AngryCorvair (Forum Supporter) said:

In reply to 03Panther :

According to

https://www.antiseize.com/PDFs/torque_specifications.pdf 

torque should be reduced by 25% when using anti-seize.

Good reference. 
My one pound reduction was mostly me making a funny!

But by seat of the pants, or SWAG method, I've prolly never reduced "torque" by that much. But having tightened many thousands of bolts, as well as torqued (with a dial, beam, or click) at least as many, my elbow has a decent cal. 

In reply to z31maniac :

The mounting face of a nut, is an area that gets ignored by most, so great method!

Fortunately anti seize "spreads" a lot, all by its lonesome (I tend to remember my nitrile gloves after I make a mess!) so the face tends to get plenty, anyway!

I have alloy wheel nuts on my Jensen Interceptor and I make sure that I am the only one that torques them unless I am standing there watching the guy changing tires do it with a torque wrench. One buzz with a torque stick/air gun will ruin them - the correct setting is only 55 ft-lbs.

I would only consider them on a car with aftermarket extended lugs, and even then the risk/reward equation is upside down for me. I had them on a Miata with stock lugs, torqued to spec, did one low-key track session and came in to find two of them missing. Presumably less of an issue with full length studs but "berkeley around and find out" as they say. I've seen lost-wheel crashes and have no desire to participate in one.  Steel for me thanks. Aluminum has lower yield strength and a finite endurance limit, I can't be trusted to do routine inspections of my lug nuts. 

I've run aluminum lug nuts forever and never really thought much about them. Really the only reason I run them is because I got them for free (they're name brand, a friend was running the car with me at the time and had a set and gave them to me).

A couple of general engineering notes:

• Once you get to ~2-3X the thread diameter, the threads are no longer the weak link, it'll be the cross section of the stud.  Most lug nuts have that (especially if you have extended studs) so the strength is fine.
• I'm not sure I'd worry too much about galvanic corrosion either.  Your studs are usually plated/coated, which would knock that effect out.  I don't think it's a particularly strong galvanic cell anyway.  I designed a bunch of long life outdoor equipment (high voltage switchgear) and I don't recall ever worrying about aluminum-steel interfaces.  As a data point: a lot of our wheels are aluminum and they're in contact with iron/steel rotors, bearings, wheel studs, etc and we don't worry too much about corrosion.

Oooh, how about carbon fiber lugnuts !!

In reply to BA5 :

Modern coated studs don't rust as bad as the cars of my youth. But if it CAN rust, anti sieze is a good thing. I'm long past the days when I could remember how far apart things on the gavanetic chart would be, but aluminum and steel are definitely not great long term. 
And a high voltage switch gear may have been designed without thought of steel / aluminum contact, but in use it either had NO-OX applied by a knowledgeable tech, or it caused some problems. May not have gotten back to the design department, but a lot of stuff don't. 

03Panther said:

In reply to z31maniac :

The mounting face of a nut, is an area that gets ignored by most, so great method!

Fortunately anti seize "spreads" a lot, all by its lonesome (I tend to remember my nitrile gloves after I make a mess!) so the face tends to get plenty, anyway!

I think you misinterpreted what I meant. The mounting face of the wheel, where it sits up against the rotor. Since most wheels are aluminum and brakes rotors steel. 

You ABSOLUTELY do not want anti-seize where nut is making contact with the wheel and applying the tq to keep it mounted. That's why you put the tiniest little dab of anti-seize at the end up the stud, rub it into the threads and remove any excess. 

In reply to z31maniac :

Your right, I simply misread. that is also a good place 

I do disagree, on a small amount on conical seat. In my experience, a small amount is a good thing 

disclaimer: this is only from street, steel lugs, and a ton of industrial bolting. No racing; no Aluminum lugs.  

The ONLY place I tolerate antiseize anywhere near the wheel/rotor/hub interface is on the threads of Porsche magnesium lug nuts.  Angry rant to follow 

I've been using AL 949 lug nuts on ARP extended  studs on my miata for years. Rattle gun them off/on 2x a year with zero issues. In the back of my mind I realize they're wear items and intend on replacing them, but it's a sunny day toy so that hasn't happened yet