Maybe they use the torque stick after tightening the nuts with an air wrench. The torque stick will click at the right torque, but that only indicates that the nuts are at least as tight as the set level.
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Torque sticks donât click. Torque wrenches click, if they are that type.
A torque âstickâ is an extension bar used on an impact wrench. They are essentially torsion springs that flex more than a regular extension. The hammer of the impact wrench twists the bar so far that the hammer stroke is all used up twisting the stick and wonât add any more torque.
They arenât more accurate than an actual torque wrench because they depend on too many variables⊠impact wrench design, speed and air pressure to name 3. Shops use them because they are quick and prevent over-torqueing the lug nuts. Iâve read recommended procedures to use the stick to get to 2/3rds of the value and use a torque wrench to apply the last 1/3rd.
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Torque sticks never go out of calibration like click type and digital torque wrenches do.
So thereâs no question if the proper torque was applied.
Tester
The torque sticks themselves may never go out of calibration, but the other variables with them do (air pressure, torque settings on the gun).
I agree they save time and are often considered âgood enoughâ for things like lug nuts.
But I canât agree that torque sticks are more accurate than torque wrenches.
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Nothing beats a bending beam torque wrench for accuracy for similar reasons. I use mine to check my click-type wrench. Just takes a short length of hex stock in appropriate sockets to join them.
Make sure you have 90 PSI of air, and impact gun set at the highest torque.
Itâs not rocket science. 
Tester
Agreed.
But âhighest torqueâ can vary from gun to gun.
So can RPM.
So can PSI.
And thatâs just to get repeatability with torque sticks. Let alone trying to be as accurate as torque wrenches.
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I didnât call anybody stupid.
The post was directed toward nobody.
Just sayân.
Tester
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Thanks for the feedback. It was flagged, and I agreed.
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Yeah, right. The quote is an obvious insult. And an insult about very reasonable and intelligent comments.
Please provide any link that agrees with your claim. None of the links I found do.
Torque sticks canât be perfect, they also wear out, right?
A co-worker broke a torque stick, not from abuse but fatigue over the years. If you rotate 10 sets of tires each day and apply 300 ft-lbs of torque to the torque stick it will not last.
A few years ago a regular here posted that he was going to buy a torque stick and keep in his trunk for emergencies but made no mention of buying a cordless impact wrench. The comments here can be interesting.
If there was ever an understatement . . .
Whatâs torque tolerance for a typical torque wrench that hasnât gone out of calibration?
Plus or minus 5%?
Torque Sticks
Now that you know how important accurate torque is on critical fasteners, we should mention another type of tool that makes accurate torque readings easier to achieve. Busy technicians in tire dealerships donât always use a torque wrench to final tighten lug nuts when mounting wheels. They should, because torque is especially important with alloy wheels. And, as we said earlier, it can affect disc brake rotors, too. But some techs may skip this final step because it takes too much time, or they canât find the torque wrench or maybe they donât even own a torque wrench.
An alternative solution for this type of application is to use âtorque-sensing sticksâ with an impact wrench to tighten the lug nuts. These tools resemble an ordinary socket with a long extension. The length and thickness of the specially heat-treated spring steel tool shaft give it a certain amount of flexibility that automatically limits the maximum amount of torque that can be applied by an impact wrench. It sounds impossible, but it works.
One manufacturer says their torque sticks can accurately limit torque to within plus or minus 5% of a specified value. Evaluation tests conducted by General Motors found that accuracy was actually even better â within plus or minus 2%!
When the desired torque range is achieved, the shaft of the torque stick begins to flex in sync with the blows of the impact wrench preventing it from overtightening the lug nut. The torque sticks may be color coded so you know which one to use with which application.
Tester
Nothing is accurate if not used properly. Dear Abby once said ânothing is foolproof in the hands of a foolâ. That is not directed at any one, just trying to point out that if someone does not understand how a tool works and how to use it, they probably wonât get the desired outcome. Any they will blame the tool.
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But that isnât what weâre discussing.
Itâs your comment that torque sticks are more accurate than torque wrenches.
As for the tolerance numbers you showed, you can be assured that the tests that produced those accuracy numbers were done in very controlled environments, not found in most tire shops or garages.
For completeness, hereâs the first part of that same trade-rag article that you quoted:
Donât use an impact wrench to tighten critical fasteners, such as lug nuts, head bolts, main bearing caps and so on.
The full article is at: www.tomorrowstechnician.com/getting-tight-with-torque-wrenches/
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From industrial supply houses Grainger and McMaster Carr
Micrometer type torque wrench⊠=/- 4% Varies a bit depending on brand, some 3% CW, 6% CCW.
From McMaster Carr, torque stick accuracy⊠=/- 10% for all that are listed and based on the price, not junk tools