The education continues. Even four months after the original post.
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lubricated studs and torque values
- Thread starter Neil Womack
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oh, so much conflicting information, my head hurts.
I used sprayed some WD-40 in my lug nuts a couple weeks ago in hopes of limiting the rust, now I don't know if that was a good idea or not.
I used sprayed some WD-40 in my lug nuts a couple weeks ago in hopes of limiting the rust, now I don't know if that was a good idea or not.
Having worked in the test lab at an aerospace fastener company, here is my take on this.
Thread lubes do matter. The "preload" or clamping force generated by torquing a nut varies with manufacturing variations and lubrication. We would use different thread lubes to "fine tune" our products.
It is better to overtighten rather than undertighten. Fatigue life is greatly shortened if too loose. Preload has to be high enough to keep the bolt or stud in sufficient tension at all times.
I takes quite a severe overload, or manufacturing defect, to break a properly sized bolt or stud. Granted, automotive hardware is built at very low cost and not much testing or inspection is done.
Thread lubes do matter. The "preload" or clamping force generated by torquing a nut varies with manufacturing variations and lubrication. We would use different thread lubes to "fine tune" our products.
It is better to overtighten rather than undertighten. Fatigue life is greatly shortened if too loose. Preload has to be high enough to keep the bolt or stud in sufficient tension at all times.
I takes quite a severe overload, or manufacturing defect, to break a properly sized bolt or stud. Granted, automotive hardware is built at very low cost and not much testing or inspection is done.
Jimbo
In short is it ok to use anti seize on lug bolts on the average car or truck?
Thanks
In short is it ok to use anti seize on lug bolts on the average car or truck?
Thanks
''Nearly all wheel bolts in modern passenger cars are coated with Dacromet, or Dacromet-type of coatings (Magni 561, for one). These are environmentally-friendly, corrosion-protective coatings that give good torque-downs. Essentially, they are flakes of pure aluminum and zinc in an organic binder. I guess you could call it a solid version of neversieze.''
If the coating was doing its job, I wouldn't find myself pulling on the breaker bar almost hard enough to break the stud off. Too often, I have found it was a good idea to protect the drive train by chocking the wheel before loosing the lug nuts. Front wheel drive components are not that robust. So far, I have not had a lug nut come loose or a stud break giving the studs a squirt of oil and torquing to 80 or 100 pound feet. I have twisted off long neglected studs. You do not always have alternatives handy when you have a flat tire. Nor do your helpers always listen to you.
Perhaps moderation is the key here.
If the coating was doing its job, I wouldn't find myself pulling on the breaker bar almost hard enough to break the stud off. Too often, I have found it was a good idea to protect the drive train by chocking the wheel before loosing the lug nuts. Front wheel drive components are not that robust. So far, I have not had a lug nut come loose or a stud break giving the studs a squirt of oil and torquing to 80 or 100 pound feet. I have twisted off long neglected studs. You do not always have alternatives handy when you have a flat tire. Nor do your helpers always listen to you.
Perhaps moderation is the key here.
Kestas
Staff member
I'd like to chime in here. I've just spent quite a few years working on bolt stud issues for trucks and autos. A colleague of mine worked for Kelsy-Hayes, has a number of patents related to vehicle corners, and was in a respected position to specify the use of lug nuts.
For trucks, one must put two drops (no more) of oil on the thread before torquing lug nuts. He also recommended the same for automotive application.
A fastener expert told me if you use never-sieze on bolts, drop the torque values roughly 10% during torquedown.
Nearly all wheel bolts in modern passenger cars are coated with Dacromet, or Dacromet-type of coatings (Magni 561, for one). These are environmentally-friendly, corrosion-protective coatings that give good torque-downs. Essentially, they are flakes of pure aluminum and zinc in an organic binder. I guess you could call it a solid version of neversieze.
Pete, labman, you've brought up an interesting point on starting friction. When retorquing wheel bolts (an issue with the trucking industry, and some passenger vehicles), one doesn't just simply crank down the bolts until the torque wrench says okay. The nut must first be loosened, then tightened to spec to avoid the sticking torque values. Otherwise, you may get weak clamp loads.
Neversieze DOES affect torque values. I've never seen it recommended. I HAVE seen it overused, where an entire truck wheel bolt stud and nut face was lubricated with the stuff with disasterous results in the lab using otherwise recommended torque practise.
For trucks, one must put two drops (no more) of oil on the thread before torquing lug nuts. He also recommended the same for automotive application.
A fastener expert told me if you use never-sieze on bolts, drop the torque values roughly 10% during torquedown.
Nearly all wheel bolts in modern passenger cars are coated with Dacromet, or Dacromet-type of coatings (Magni 561, for one). These are environmentally-friendly, corrosion-protective coatings that give good torque-downs. Essentially, they are flakes of pure aluminum and zinc in an organic binder. I guess you could call it a solid version of neversieze.
Pete, labman, you've brought up an interesting point on starting friction. When retorquing wheel bolts (an issue with the trucking industry, and some passenger vehicles), one doesn't just simply crank down the bolts until the torque wrench says okay. The nut must first be loosened, then tightened to spec to avoid the sticking torque values. Otherwise, you may get weak clamp loads.
Neversieze DOES affect torque values. I've never seen it recommended. I HAVE seen it overused, where an entire truck wheel bolt stud and nut face was lubricated with the stuff with disasterous results in the lab using otherwise recommended torque practise.
**** , I never really worried this much about torquing lugs! I just hit um up to 80 ft lbs, and retorque after about 100 miles. You'd be amazed how lose lugs can get if you don't retighten every once in a while.
Having paid attention to torque values, I've never had to use excessive force on unlubricated lug nuts, except when work was done by others...
There ARE uses for anti-seize, including spark plugs, exhaust parts, and (my favorite) the bolts that hold on your lawnmower blades.
There ARE uses for anti-seize, including spark plugs, exhaust parts, and (my favorite) the bolts that hold on your lawnmower blades.
Isn't that mostly just true for aluminum alloy wheels, or maybe all alloys? I find my steel wheel lug nuts seem to always seem to get tighter over time.quote:
Originally posted by Drew99GT:
**** , I never really worried this much about torquing lugs! I just hit um up to 80 ft lbs, and retorque after about 100 miles. You'd be amazed how lose lugs can get if you don't retighten every once in a while.
I had a set of aluminum aftermarket wheels on a Mustang I previously owned. I used anti-seize on the wheel lug surfaces, where the lug nuts tightened against. The anti-seize gave a better "feel" when torqueing the wheels down, and prevented galling of the aluminum from the steel lug nuts. They never gave a problem with loosening up, but I did use the anti-seize sparingly.....
Perhaps, I've only noticed it on aluminum wheels.quote:
Originally posted by acranox:
Isn't that mostly just true for aluminum alloy wheels, or maybe all alloys? I find my steel wheel lug nuts seem to always seem to get tighter over time.quote:
Originally posted by Drew99GT:
**** , I never really worried this much about torquing lugs! I just hit um up to 80 ft lbs, and retorque after about 100 miles. You'd be amazed how lose lugs can get if you don't retighten every once in a while.
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