I'm pretty sure I was talking about something else altogether, on account of it feeling less sciency and technical in my head. But what you were saying sounds very interesting. Especially if there was an easy to follow rules of thumb involving long division and the inch fractional system. Aaaand I know I'm asking for a miracle here, but all that converted into good ol' boy and I think we'd really have something.

But that's begining to sound like the "feels good" method I was referring to earlier.

 

I don't think it was mentioned yet cause most folks know about the tightening pattern but yes always tighten the lugs in the proper sequence.

 

Haha, you'd be amazed at things that people forget to do, or mess up, that most people consider to be common knowledge. I'm talking stuff you wouldn't even offer to share for fear of offending the other person, that obvious. Lug torque pattern falls into that category.

 

One problem with turn of the nut is you have to have a starting point where everything is mated up. As you know depending on whether you are using lube or not that mate up torque, which would be just tight enough to get the air out of the way,is going to be hard to judge dry versus lubed.

The beauty of the dry torque is that it's based on steel to steel friction, something that can be fairly accurately measured and duplicated by average guys with a torque wrench. Add lube and it's going to be easier to turn the nut and turn it further with the same torque as dry, over tensioning the stud! Then is the lube only on the threads or is it on the nut face too? That's why dry is the way to go. And then you ensure the nut doesn't vibrate off too.

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I'm going to go out on a limb and say 99% of lug nuts that fall off were only finger tight. Which brings up an interesting point in my opinion. Finger tight. I'm sure it's different depending on whose finger is being used. But that's the start of the torque spectrum isn't it. And between there, proper torque and stretched threads is a very minimal amount of degrees rotation. Back to that dry torque, the threads need to be clean, properly cut, and rust free or everything is out of spec? Finger tight on fresh threads vs rusty threads are miles apart. Anything passed finger tight is torqued to something. Which is waaaay better than nothing. Then after you put the wrench to her, there's so much rotation of smooth even pressure, then it starts to bind. That's got to be the start of the end of the torque range up to the over torque range, or did I miss the mark? Somewhere in there, right at the end of the smooth tightening, I think there is a couple of degrees of rotation where you're at the proper torque. Which is what I was talking about having someone test. A little more or less than that sweet spot has got to be in spec or more tires would fall off or more studs would break. And I think we can all agree that anything between lug nuts falling off and having to jump on the four way to get lug nuts off(which is obviously somewhere before breaking studs) is a good place to hang out.

 

When we are talking lug nuts and studs they are pretty much smooth steel to steel and to the rims steel to steel or aluminum. I think the dry friction factors are virtually the same. and yes the values assume clean dry and rust free. But even if a little rusty the difference between that and clean will be nothing like the difference between dry and lubed. When we say 140 foot pounds of torque that usually means the middle of a range of acceptable torque slightly more or less and you're still good.

If you have rust then you didn't protect your threads...if you do get out a wire brush and give em a tune up.

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All I know is that one day 100% of my 4 lug nuts on my Falcon fell off. It was a long time ago and I'm not sure if that tire was on there since the PO had it or if I was involved. Back then I was going by the tight like hell plus half a turn method.

Later I got a torque wrench and learned how to use it.

 

How do you factor in the the weight of the vehicle and how it relates to your torque readings? The lug nut does fit up in the conical taper of the rim. And everyone lets the rim down to hold the wheel from turning after they get the lug nuts "sort of tight". You know the lug nut is squirming up in the rim some more when you are tightening it with some of the weight of the vehicle on it.

Most shops now just use those colored torque extensions made to fit onto impact guns.

 

Hmm, haven't seen the colored extensions before. Sounds like it's a torque limiter of some sort? My local tire store uses torque wrenches.

As for vehicle weight and the relation to torque wrench readings I think it is nil compared to the torque required to effect 60 percent of yeild stress in the stud. The lugs are fitted up to the conical taper holes in the rim while on the jack. Once you have two lugs tight on the ground it further centers the rim holes on the studs/nuts. I go round the star pattern at least twice and usually there is little or no nut rotation on the second go round...but I like to check. Once centered and clamped on two or more lugs the friction in the torquing operation is independent of vehicle weight. On the check round weight is not in play as all lugs are centered and clamped.

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Torque Sticks

 

Seems like a good idea. All you need is the right one and a breaker bar for your tire tool kit. Do they ever wear out? What about calibration?

Doing some research this morning seems like a lot of folks use them in their air wrenches with a lower rated one and then final torque with the torque wrench. If you have one you should probably check it once in a while with a torque wrench, yes?

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Some are made better than others, I'd test it out of the box. And even if they are off, as in weak. You can still go hog wild with an impact and not have to worry about over torqing. Handful of videos on YouTube about. Opinions go both ways.

 

I ran a few quick numbers on it. Seems the clamping force in the stud can vary a bit depending on the condition of the threads and the diameter. The clamping force calcs out to be roughly 15,000 pounds for a 9/16" stud. Truck weight is 8800 pounds GVW according to my sticker on the door post. Say .6 of that weight is on an axle and that split between two wheels and that divided up among 8 studs is 330 pounds each. So that conservative estimate of vehicle weight per lug is about 2% of the contribution and it's only applied to the top half...

I used T = 140 ft-lb and K = 0.20 and solve for P. Note that when going from plain to lubricated the clamping force doubles to 30,000 pounds!!!!!!!!

T = (K D P)/12

• T = Torque (ft-lbs)
• D = Nominal Diameter (inches)
• P = Desired Clamp Load Tension (lbs)
• K = Torque Coefficient (dimensionless)

The value of K is a dimensionless torque coefficient that encompasses variables such as those listed above, as well as the most significant variable, friction. The value of K can range from 0.10 for a well lubricated/waxed assembly, to over 0.30 for one that is dirty or rusty. The values we used when calculating our values are:

• 0.10 = Waxed/Lubricated
• 0.20 = Plain, as received condition, slightly oily
• 0.25 = Hot-Dip Galvanized

From: https://www.portlandbolt.com/technic...ained-sort-of/

 

A cool device but for me it will never replace the torque wrench. Read the 1 star reviews before purchasing one!

I'm using an electric impact to run the nuts up on the lugs. It's no sweat to stop before "impact". Then use the torque wrench from there.

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I used a speed handle just now