How the right fastener can prevent hardware failure on track

volvoclearinghouse (Forum Supporter) said:

One final thought- use either locking compound, or lubrication on threads.  This sounds counter-intuitive and contradictory, but there's a reason.  A properly torqued bolted joint will resist loosening- and the best way to obtain proper torque is with lubricated threads.  Loctite will "lock" a fastener, but it also helps lubricate it on installation, so that correct torque can be applied.  If you're not using a thread locking compound, always use antiseize or similar to help make sure the threads engage fully and you get a "true" torque on the fasteners.

I understand and agree with the reasoning behind this (it's why ARP supplies their lube with all their products), but there's one critical exception--when you're dealing with a torque spec that assumes the threads are dry, if you lubricate the threads, you will keep turning and turning until you damage something. Been there, done that, learned my lesson.

I think the answer to Floating Doc's question about lug nuts is along the same lines.

obsolete said:

volvoclearinghouse (Forum Supporter) said:

One final thought- use either locking compound, or lubrication on threads.  This sounds counter-intuitive and contradictory, but there's a reason.  A properly torqued bolted joint will resist loosening- and the best way to obtain proper torque is with lubricated threads.  Loctite will "lock" a fastener, but it also helps lubricate it on installation, so that correct torque can be applied.  If you're not using a thread locking compound, always use antiseize or similar to help make sure the threads engage fully and you get a "true" torque on the fasteners.

I understand and agree with the reasoning behind this (it's why ARP supplies their lube with all their products), but there's one critical exception--when you're dealing with a torque spec that assumes the threads are dry, if you lubricate the threads, you will keep turning and turning until you damage something. Been there, done that, learned my lesson.

I think the answer to Floating Doc's question about lug nuts is along the same lines.

Yes, throwing anti-seize onto bolts willy-nilly and then torquing to a spec that assumes "clean, dry threads" is a good way to strip the threads off the fasteners.

There's really no such thing as a "true" torque, even with lube a lot of the force is going into overcoming friction.  If you really care about fastener pre-load then there are other ways of measuring it that are more accurate (angles or bolt stretch)

In reply to codrus (Forum Supporter) :

The problem is, how do you define "clan and dry"?  Almost all fasteners are going to have some oil or something on them, unless you fastidiously degrease them and then don't touch the threads.  And ensure the hole is clean and dry as well, somehow.  Obviously, if the spec calls out torque 'x' for "clean and dry" and I have antiseize on the threads, I'm going to consult my torque calculations for the particular fastener diameter and thread pitch and grade and determine what the equivalent 'y' torque should be.  

Yes, torquing is not the most accurate method of setting bolt preload- but it is quite easy.  "turn of nut" has its own challenges, and measuring bolt stretch or actual clamping load is usually not practical.  And because of friction, variances in coatings and "incidental" lubrication, 'Dry Torque' is generally not as accurate as "Wet Torque".  

Floating Doc (Forum Supporter) said:

In reply to volvoclearinghouse (Forum Supporter) :

 If you're not using a thread locking compound, always use antiseize or similar to help make sure the threads engage fully and you get a "true" torque on the fasteners.

I believe I have in the past asked about using anti-seize on Lugnuts. I believe that the consensus was that they should be torqued dry. Could we address that question?

I always always always anti-seize lug nuts.  Not just for torque- I 've had lug nuts seize to studs, and steel nuts do not play well with aluminum wheels.  Antiseize, definitely.  As for what torque to use, as I mentioned before, figure out what the thread pitch and diameter is, and the grade, and then you can figure out what the torque's supposed to be.  For example, a 1/2"-20 lug nut (assuming Grade 8 equivalent) would have a dry torque of 120 ft lbs, so I'd use 90 ft lbs with antiseize.  

If using an impact, that's equal to about 11-12 "ugga duggas".  

https://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf

For reference.  

In reply to Appleseed :

Rust. Rust is natures' threadlocker. Cross=threading is accidental threadlocker.

volvoclearinghouse said:

The problem is, how do you define "clan and dry"?  Almost all fasteners are going to have some oil or something on them, unless you fastidiously degrease them and then don't touch the threads.  And ensure the hole is clean and dry as well, somehow.  Obviously, if the spec calls out torque 'x' for "clean and dry" and I have antiseize on the threads, I'm going to consult my torque calculations for the particular fastener diameter and thread pitch and grade and determine what the equivalent 'y' torque should be.  

Yes, torquing is not the most accurate method of setting bolt preload- but it is quite easy.  "turn of nut" has its own challenges, and measuring bolt stretch or actual clamping load is usually not practical.  And because of friction, variances in coatings and "incidental" lubrication, 'Dry Torque' is generally not as accurate as "Wet Torque".  

If it matters, you clean the rust/etc off the threads with a wire brush, squirt it with brake cleaner, and then handle it with clean gloves.

I suspect the conversion charts between the "clean/dry" spec and the "with anti-seize" specs are going to introduce more error in your spec than using the above procedure.

Personally I only use anti-seize on fasteners where the spec explicitly calls for it, or for those that I know are likely to be difficult to get off later (exhaust nuts, mainly).  Otherwise I leave it in the jar -- for regular stuff it's going to cause more trouble than it's worth.  I never use it on lugnuts, and in 25 years the only time I've ever had a problem with one coming off was when a tire shop cross-threaded it.  OTOH, I live in California where things don't rust much.

In reply to codrus (Forum Supporter) :

"OTOH, I live in California where things don't rust much"

Bingo.  I grew up in Western NY, where new cars have rust on them.  I've been using anti-seize on lug nuts for 20 years, and the only time I've ever had a problem with lug nuts coming off was one time at a race where someone used the "ugga dugga" method of torquing them and (unknown at the time) the compressor was unplugged and only had like 30 psi.  My fault, I should have rechecked them, or insisted they torque them properly.  That was 10 years ago, and I still kick myself for that goof up.  Luckily, no one was injured and the damage was minimal...and, if I'm being honest, somewhat hilarious.  

The conversion charts don't introduce any additional error, they simply assume a different coefficient of friction on the threads/ fastener face. My point is, it's a lot easier to control that friction coefficient lubricated than it is "dry".  Also note, the plating on the fasteners makes a difference in the "dry" torque...so do you know, for certain, if you're dealing with an unplated bolt, or zinc plated or...?  

I feel this is a productive conversation to have, and while there's certainly a lot of hammer mechanics who think they know better than the engineers who designed stuff that do more harm than good when touching a wrench to something, I'm fairly confident that my 8 years of engineering edumacation and 20+ years of experience working on cars, buses, and trains have something to do with the ability to make a determination what works and what doesn't.  Caveat Emptor, when in doubt, it's usually safer to do what the manual says.  

I have seen anti seize (or other lube) be blamed for causing a problem, but usually there were other contributing factors

But have seen MANY more problems from NOT using it - or not using enough. 

I have seen lugs loosen; both dry and lubed. But it has NEVER been because of lube!

Concerning the Nylock nut; Do not reuse after removal...replace with new...

I really enjoyed and appreciated this article. I have a copy of Carroll Smith's "Nuts, Bolts, Fasteners, and Plumbing" on my bookshelf, and I recommend it to folks, too.

Nice article.

Star washers are used to make sure a faster has a good ground, they do a good job cutting through a paint layer down to the base metal.  As stated, they aren't the best lock washers.

Totally agree Carroll Smiths book is excellent. In fact all his book are very good.

Also check out stage8.com these product are terrific if you have a critical application. 

Finally remember bolts and studs are only springs so the longer they are the better they work at retaining clamping load consistently. Consequently short fasterners especially ones clamping thin components like sheet metal need a lot of help.

In reply to wombat1954 :

"Springs" is not really accurate. They do hold by the effort of pushing a load up an inclined plane. (wrapped around a helical axis ).  Measuring stretch (with known properties of the metal used in the fastener) will give a indication of  clamping force, but it's the resistance to moving up that ramp that does the holding.

 
Stage 8 does make some cool stuff!

Appleseed said:

Remember,  cross threading is nature's Loc-Tite.
I thought that's what sand was for.

Just a reminder

Blue loctite for removal without heat.

Red loctite for removal with heat >300F.  Commonly used where there is only one nut, e.g. Output flange, axle nut.

ProDarwin said:

What do you call an ovaled nut?  Does that still fall under prevailing torque?

They are common and cheap, although usually designed for a specific application.

Sometimes I make my own by crushing a nut in my vise.

I call them scrap, they tend to damage the threads of the bolt on installation.

#torquestripeallthethings

It's so disappointing to find out old articles are constantly reposted with + membership access only.  Imo, if an article has been published for general public consumption (or membership+ only access has been lifted, etc), that should stay in effect forever.  Let's not be Indian givers guys.  

How is this not viewed by more members as a deceptive and misleading publishing practice?  

A few comments on Loctite. The anaerobic adhesive is dependent on an active metal surface to cure. This is fine with most fasteners, but means it is not as effective on stainless steel fasteners. Also, the anaerobic adhesive is a stress cracking agent for many plastics and should not be allowed to get on any parts made out of a plastic susceptible to solvent stress cracking. This usually means amorphous thermoplastics, a group which includes transparent plastic such as acrylic and polycarbonate (aka Lexan).

Any reader of Carroll Smith's books can tell you that split lock washers belong in one place only, the round file. Throw them away! All of them, every last one of them!

I only use star washers for electrical grounding.

Should have used Rustix brand fastener adhesive. Rustix goes to work fast, using the all natural power of corrosion to permanently bond fasteners together. Available at any Mike's hardware store, Rustix will bond your fasteners together so tightly, you won't even be able to tell where the bolt ends and the nut begins.

"Rustix: Nothing sticks like Rustix! Securing fasteners the HARD WAY since 2018."