Too old to torque

As a noodle-armed 28 year old with a Navy veterans spine, i can confirm a longer bar makes all the difference. I keep a 3-4 foot breaker bar in the Jeep at all times! A length of pipe can serve the same purpose in a pinch. The long breaker bar doubles as a beating stick for the road rage types.
 
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Artsifrtsi said:
Guys... do not use cheater bars on a torque wrench, and only use the extensions if they came with it... That is a good way to invalidate the torque applied to what you are working on... If you need more leverage, get a longer wrench, or use something to load the wrench at it's fulcrum point (usually indicated by an indicator of the handle) This is the center point of where to apply your force. (in center of your grip)
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I see from your profile that you are a metrologist, so I'm hoping to learn something today because you've probably forgotten more about torque wrench use then I ever learned. I've had several of my clicker wrenches apart over the years (including the big T&E Tools one I posted about above). In looking at how they operate, and using my engineering experience to guide me, I concluded years ago that where you apply the force on the wrench to develop the moment (torque) does not matter, assuming that the individual components are rigid bodies (designed so that deflection under load is inconsequential.) Also, in the mechanical engineering (and physics) world, a fulcrum is a pivot point. If the machined ring in the grip of your photo is the "fulcrum," I'm thoroughly confused.

Can you please explain how the position of a hand on the grip of the wrench affects the torque applied?
 
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Yes, was shooting from hip with lack of sleep. Terms incorrectly applied.

It matters where the moment is applied, as it can and most of the time does make a difference between a wrench being in or out of tolerance (most wrenches are 3% accuracy). The ring is the optimal distance from the head to properly load. There are proper extensions for wrenches, and the whole wrench will get tested with the extension as well.

Even, and moreso, on a beam wrench with a pivoting handle it is important to have the handle pivoting on the moment.
 
Artsifrtsi said:
Yes, was shooting from hip with lack of sleep. Terms incorrectly applied.

It matters where the moment is applied, as it can and most of the time does make a difference between a wrench being in or out of tolerance (most wrenches are 3% accuracy). The ring is the optimal distance from the head to properly load. There are proper extensions for wrenches, and the whole wrench will get tested with the extension as well.

Even, and moreso, on a beam wrench with a pivoting handle it is important to have the handle pivoting on the moment.
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I'm still confused. As the operator of the wrench, I am applying a force to the wrench, not a moment. The moment (a/k/a torque) is developed at the head, with the moment's axis being the centerline of the square drive, which is inline with the fastener's centerline. I agree that where the moment is applied is important, but that has nothing to do with where the force is applied (at the handle).

For instance, assume my torque wrench is 24" from the centerline of the square drive to the center of my grip and set to click out at 20ft-lb. If I apply a 10lb force at the grip, the moment developed at the fastener can be calculated by multiplying that force times that distance - 10lb x 24" = 240in-lb, or 20ft-lb. And the wrench clicks out.

Now, I've always assumed that, since the handle is rigid, and the mechanism inside doesn't "know" where I place my hand, if I move my hand half-way between the head and the grip and now apply a 20lb force, the new moment developed is the same - 20lb x 12in = 240in-lb, or 20ft-lb. And that the wrench clicks out.

Why is this a poor assumption I've been making all these decades?
 
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Artsifrtsi said:
It matters where the moment is applied...
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Now this makes sense to me, but again, it has nothing to do with where I grip the wrench. If the centerline of the square drive on the wrench is offset from the centerline of the fastener, like when using a crowsfoot wrench, the user has to account for that offset (depending on the angle used with the crowsfoot), using the offset torque formula (not sure where I got this image in my files):
1715971451759.png


Incidentally, I occasionally test GearWrench products as part of their "GearHeads" consumer test group. A couple years back, they sent me their open-end interchangeable torque wrench to review. Here's the production version (source: Amazon.com):
1715970539979.png


I don't know if they fixed it for production because it's not evident from that photo, but when I measured the distance between the fastener centerline and the face of the attachment point on each wrench, this distance varied by wrench size. In order for the wrench to work properly, they'd all have to be the same distance. I was flabbergasted that a tool company didn't understand offset torques, and told them (oddly, I'm still one of their "GearHeads")!

That brings me to my final question:
Artsifrtsi said:
There are proper extensions for wrenches, and the whole wrench will get tested with the extension as well.
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Are you saying that, for wrenches used with an extension, as in the first picture above, using the offset formula isn't good enough? You'd have to re-calibrate using the extension? And at a certain angle? I've never heard that before. I've worked for two powersports companies and three top-level professional motorsports teams, and all of them simply used the formula when an extension was used. We did have our wrenches calibrated, but not with extensions - we just used the formula.
 
sab said:
Are you saying that, for wrenches used with an extension, as in the first picture above, using the offset formula isn't good enough? You'd have to re-calibrate using the extension? And at a certain angle? I've never heard that before. I've worked for two powersports companies and three top-level professional motorsports teams, and all of them simply used the formula when an extension was used. We did have our wrenches calibrated, but not with extensions - we just used the formula.
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So, this gets a little bit into best practice, and some other issues… chances are, IF the extension is made to work with that particular wrench, then the Manf PROBABLY did their testing to come up with the formulas to compensate. If not by the same manf for the same model wrench, you could have it cal’d with it once, and then calculate your own offset for that wrench and be ok.
 
SouthernTJ2000 said:
Few weeks back a co-worker was out on vacation so I had to step in an assemble his tool for a test. It was so hot it had to be done that Friday, so it could sit and wait until the following Thursday, but I digress. I got to use this bad boy. Its a six footer, I've never seen anything like it. It threads together in the middle. and goes to 1200ft/lbs I believe. We were only going to 350ft/lbs, but it was cool using it.

Side note, one of the other guys helping only weighs about a buck fifty, it was kicking his butt. I've got more "ass" so it wasn't to hard.

View attachment 527396
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I love those reach truck forklifts. Used to destroy so many carpet displays at Lowe's.
 
Artsifrtsi said:
If not by the same manf for the same model wrench, you could have it cal’d with it once, and then calculate your own offset for that wrench and be ok.
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I don't understand calibrating with the extension. It's not that simple because the extension can be used at multiple angles to the wrench, and each angle changes the the rate at which the torque setting changes, linearly, as you turn the handle. Wouldn't the metrologist doing the calibration have to change the spring in the handle to a different spring rate depending on the angle of the extension? Is that practical?
 
185 ft-lbs.... That sounds like highest impact setting and about 6-8 ugh-dughs... Maybe 10...

You guys are breaking out measuring devices for this...? Nerds.
 
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FarFire70 said:
185 ft-lbs.... That sounds like highest impact setting and about 6-8 ugh-dughs... Maybe 10...

You guys are breaking out measuring devices for this...? Nerds.
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Lmfao! Yeah at 185 ft-lbs it's just showing off.
If I recall, the factory service manual for my old Harley said something like,
"Using a 1/2 inch drive socket and 2 foot breaker bar, torque the clutch basket nut as tight as possible, then strike the handle of the breaker bar several times with a heavy mallet to seat the clutch basket nut."
 
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sab said:
I don't understand calibrating with the extension. It's not that simple because the extension can be used at multiple angles to the wrench, and each angle changes the the rate at which the torque setting changes, linearly, as you turn the handle. Wouldn't the metrologist doing the calibration have to change the spring in the handle to a different spring rate depending on the angle of the extension? Is that practical?
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Handle extension is what is being discussed. Like a cheater bar.
 
Artsifrtsi said:
Handle extension is what is being discussed. Like a cheater bar.
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True, that was the original discussion topic, but you were leading me down a different path of discovery by specifically responding to a line of questions I posed regarding extensions at the socket end:
1716123262679.png


So far, you have not changed my mind. The clicker type torque wrenches work the same no matter where your hand is on the handle because the outer tube is rigid, and no matter where you apply the force, the internal mechanism responds the same. And, applying a cheater bar carefully will give reliable torques. Carefully means don't let the bar mess up the adjustment mechanism and don't let the bar apply a concentrated load that bends or dents the outer tube.
 
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