Use Of Anti Seize On Automotive Wheel Lugs & Studs 2

[billt460]

This subject comes up from time to time. And usually when it does, it falls into the same rabbit hole. Perhaps that is because it never seems to be examined from a common sense, practical standpoint. Everyone always seems to be too quick to pull out their engineering manuals. First off, let's examine the 2 biggest examples that come up against this practice. First is that the use of anti seize products on wheel studs will facilitate the loosening of the wheel nuts attached to them over time. The second is that the use of anti seize will cause over torqueing of the studs themselves. Thereby weakening and or stretching them, to the point of outright breaking them off.

Let's first look at number 1. If the use of the anti seize products would in itself cause the studs to become loose over time, it only stands to reason it would do much the same in most all other threaded applications it was used in. We know for certain that is not the case. Anti seize is used in several other automotive applications without any loosening of bolts or nuts it was applied to over time. Cylinder head bolts. Water pump mounting bolts. Spark plugs, and shock absorber studs and nuts, just to name a few. Anti seize is not only recommended in many of these applications, in many cases it is a must to avoid broken bolts in the future when they are removed.

Now let's examine number 2. In all forms of fastening with threaded nuts and bolts, a lubricated thread will require less torque to achieve the same clamping force, (or "pull" on the stud or bolt), as the same fastener that is used dry. So in this regard the statement is true. The same foot pounds of torque applied to a lubricated thread will achieve a greater amount of stress on the bolt or stud, than the same torque applied to a dry threaded fastener of the same size and type.

This additional force in the case of most automotive wheel studs is around 20% to 30%. So when anti seize is applied, all that is required is to apply around 25% LESS torque to accomplish the same task. The nut will not come loose. Nor will it be subjected to any additional stress. For example, if a dry wheel nut is rated to be torqued at 100 ft. lbs. when torqued dry. Then simply reduce the torque to 75 to 80 ft. lbs. if that stud has anti seize applied to it. Proper torque is what keeps nuts and bolts properly tightened..... NOT rusty, dry threads.

So in conclusion there is absolutely nothing "wrong" with using anti seize on lug nuts and studs. Any more than it is in other applications. It will not only transfer torque easier. It will also prevent rust and corrosion of the threads. And by doing so will facilitate the easy removal of said wheel nuts when the time comes. Without heavy, unnecessary torque that very well might cause the stud to snap off.

I have used anti seize on all of my vehicles wheel lugs and studs for the last 50 years. And I have NEVER had a wheel stud break. Or a wheel nut come loose... EVER. Nor have I ever heard of one doing so. With that said, I have seen on several occasions, studs break off from being frozen, rusty, and corroded. So in closing I will say I will continue this practice, simply because I have never seen, or come across a situation that has shown me it would be better to not.

 

[DVWE]

The number of wheel nuts I have replaced because they came loose from the use of anti-seize = 0

The number of seized wheel nuts/studs I have replaced because they were rusted, corroded, or otherwise not properly treated with anti-seize = too many to count

The devil is in the details; she also wears prada.

 

[oldestguy]

Perhaps someone will come on and indicate what conditions are present for the vehicle manufacturer coming up with torque specs for their vehicle. I suspect no lube, meaning that with lubrication more rotation of the nut takes place, giving a tighter pull against the wheel. Maybe OK as long as stud is not over stressed into yield, or the wheel nut contact zone is not into yield. With typical studs, I suspect the stress-strain curve has very little remaining yield strain left before tension failure. I'd like to see the manufacture's test stress-strain curve and where they like to see the working stress sit. Then relating that to torque required. Maybe the safety factor allows for lube.

 

[MikeHalloran]

The torque specs provided are for new, clean, lightly oiled threads, because that's how fasteners arrive at the car factory; they don't have an inventory of fasteners in any other condition.
At least that was true 50 years ago when I worked in a factory cranking out 10,000 axles a day.





Mike Halloran
Pembroke Pines, FL, USA

 

[BridgeSmith]

Number of lug nuts I've put on and taken off over the years - too many to count.

The number of lug nuts I've used anti-seize compound on - 0.

The number of lug bolts I've broken - 0

If I was going to put anything on the threads of the lug bolts on my vehicles, I'd use a low-strength threadlocker. The last thing I'd put on something that would kill my family if it came loose is something to help it come loose.

Edit: I also exceed the torque specs by about 30% every time.

 

[kingnero]

@ HotRod10: on steel or aluminium rims?

general consensus is that grease or anti seize plays havock with the torque, because of the excess that comes under the bolt head. This lowers the friction significantly, causing overtorqued bolts (or when using nuts on studs, same principle applies).

Sparingly use of anti seize (making sure nothing comes of the front mating face) causes a slightly higher fastening torque, which is not necessarily a bad thing.

 

[BridgeSmith]

@ kingnero: Both steel and aluminum. I've never put anything on the threads for lugs. I just make sure I don't crossthread them, torque them 30% or so over what the manual says, and I've never had a problem. It takes some muscle to loosen them the next time, but it's good exercise (for my teenage boys, that is).

One other observation that argues against using anti-seize - I've never seen a tire shop that does it, nor an OEM.

 

HotRod10 has it exactly right.
I recently took delivery of a pre-owned SUV from a dealership who did just about everything wrong they could have with the wheels.
(1) The wheel studs are lubricated, meaning I can look forward to stretching/breaking one or more over the years. It has happened to me before, and it's not a cheap repair. Regardless, I never permit lug tightening without me personally observing.
(2) The tires are inflated with nitrogen. This has modest benefits, but it's not something one should ever pay for. What nitrogen does is reveal the gimmicky thinking of the dealer. What other gimmicks do they apply in the service bay?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[billt460]

Tire shops are the last place to use as an example of what to do. Most employ minimum wage kids who go crazy with air guns. They over torque EVERYTHING because they don't want to be responsible for anything coming loose. If you use anti seize, and REDUCE the applied torque by 25% to 30% over the recommended value, you will not overstress or break anything. And still have the same transfer of torque, and clamping force applied to the wheel.

Over torqueing dry studs IS over stressing them, period. And is asking for a disaster in the process. Much more so than having a properly torqued wheel come loose from using anti seize. Which doesn't happen. As I said, if anti seize itself caused the loosening of threaded bolts. Spark plugs, cylinder head bolts, and water pumps would be leaking, and falling off left and right. They don't.

 

[DVWE]

Actually, tire shops - quality tire shops that is - are good examples to use. Just like the one that I was born and raised in, the rule of thumb is simple; old, rusted on lug nuts that are difficult to remove should be wire wheel brushed clean and apply a LIGHT coat of anti-seize. Newer vehicles in which the lug nuts are removed normally and easily do not need an application, but is good practice to put on, again, a light coating to prevent future rust and corrosion.

The key is light or sparing use of anti-seize and NOT liberal usage.

Personally, I've done thousands this way and my father probably on the note of tens of thousands this way. Never has he had a complaint of a lug nut falling off or did he notice one was loose at a later date from the use of anti-seize.

The devil is in the details; she also wears prada.

 

[DVWE]

EDIT:

The STUDS should be wire wheel brush cleaned, and a light coat of anti-seize applied to the threads of the studs, and not to the mating face as kingnero noted.

The devil is in the details; she also wears prada.

 

[oldestguy]

The above comments are fine, but on what basis does the manufacturer spec torques on wheel nuts? I'd bet no anti-sieze.

 

[BridgeSmith]

Tire shops may be partially staffed by inexperienced young people, but the policies that they are required to follow are set by management, who bear the responsibility and liability for the work performed.

As far as overstressing the studs, it depends on whether you're talking about torsional stress or tension stress. Lubricated threads will have higher tension stress at the same torque than 'dry' studs. Overtorquing lubricated studs is a double whammy for the tension stress.

 

[DVWE]

Here is an old thread I vaguely remembered just after I joined this forum. Same topic, very good read and some very valid points are made.

https://www.eng-tips.com/viewthread.cfm?qid=229718

The devil is in the details; she also wears prada.

 

[BridgeSmith]

Interesting thread DVWE. Seems this is an old argument.

As far as the increase in tension due to lubricating the threads, using the calculator at Engineer's edge, the tension is fairly low, and doesn't change alot with the coefficient of friction shown for "lubricated" vs. "steel". At 50 ft-lbs of torque on a 1/2" stud, it was about 45ksi for lubricated vs. 36ksi for steel. Several bolt manufacturers show this same approximation, with a factor of 2 difference between "Waxed/Lubricated" and "Plain, slightly oily". Granted, from this article it appears that bearing face friction (in this case, between the lug nut and the rim) is more prominent than the thread friction, so lubricating the threads only should not change the bolt tension substantially (maybe a 10% increase, probably less).

 

[CWB1]

I try not to reinvent the wheel, especially time-tested tasks that are safety critical. The factory fastener coatings do an excellent job of preventing rust, galling, and other issues, anymore its extremely rare to see a broken wheel stud that hasn't seen the worst abuse. The issue anymore is corrosion creating an interference fit between wheel and hub flange.

 

[DVWE]

You'd be surprised, CWB1.

There are a few things to consider as pointed out in that old thread. Studs are simply not equal between manufacturers (ahem...Volvo). Also, a California or Arizona car won't see the weather harshness of a farther east car, especially those that are subject to ice melt on the roads (i.e. mag chloride).

I'll still help my old man on an occasional Saturday here and there, and we have seen the early signs of corrosion on the wheel studs on some cars as new as 2014. I will admit however, these instances are far and few in between, and for the most part, the anti-seize stays on the shelf.

The devil is in the details; she also wears prada.

 

[billt460]

Rain exists everywhere. Less in some places, (desert), while more in others, (Midwest rust belt). Wheel studs and nuts are one of the most exposed threaded fasteners in a vehicle. Especially today with the widespread use of alloy wheels and their exposed lugs and studs. Road spray, (both rain / snow, and salt), will induce the rust and corrosion process all but immediately. I can't think of a more common sense application for anti seize, than on wheel studs and lugs....... With the proper torque.

 

[CWB1]

Hi DVWE, I grew up in the family shop in NY and was a tech for a decade before becoming a powertrain engineer. Nothing really surprises me anymore regarding build quality, but IME stud coatings in recent decades are excellent. I'd wager <1% of vehicles will ever need a single replacement despite a lack of lubrication, washing, maintenance, etc otherwise. Personally, I haven't gotten into wheel or hub component engineering, but the ethical side of me prefers not to second-guess those that have as many times there is testing and tribal knowledge of otherwise unforeseeable circumstances involved. I cannot recall ever seeing an OE maintenance manual that suggested lubricating stud threads but have seen several that directed folks not to. I'm sure there's good reasons for that just as there's good reasons why some OEs still use left-handed threads on the driver's side. Regardless, given the low likelihood of breaking a stud and the fact that replacement is a quick and easy task, I'll skip the lube.

 

Rain exists everywhere. I welcome regular rain, to rinse the road salt off the various exposed or weakly coated components in my wheels and undercarriage. And if it's raining it means it is not cold enough to snow.
Visit S Ontario sometime if you want to see some very crusty 5 year old wheel studs.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."