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WHAT?????
The guy in the OPs video took Park Tools' 2 minute video and threw in a bunch of math to over-explain the following;

The relative positions of the clutch vs socket attachment in a click-style TW complicates simple tests of accuracy (i.e., hanging a weight off of the wrench). Make sure you hang the weight off of the center of the handle if you're going to verifity the accuracy of a TW.

If you're happy to assume it works as-is, just put your hand on the handle like you would probably do anyway.

Or use a beam-style wrench.

EDIT: Here's the Park link (fwd to 1:15)

I don't quiet understand the math of it either but I'm not going to spend the time to figure it out. I think it has to do with the clutch giving way at a set shear force, not torque (4:20 and 7:20 in the OPs video). The wrench is setup so that that shear force equates to a torque at the bolt but that's only accurate if the shear force is applied to the correct position on the lever arm (the center of the handle).
 

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I know the physics, I have found errors in physics books and been in arguments with teachers over misapplication of it's theorems.
 

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Discussion Starter · #7 ·
I know the physics, I have found errors in physics books and been in arguments with teachers over misapplication of it's theorems.
That's what flat earthers say... then never show their work. :rolleyes:

So go on.... show your math. Prove he is FOS.
Oh... and then get yourself a torque sensor and prove that the Park video is FOS too.
Because they prove the math.
#Physics
 

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If you use a (click style) torque wrench, you really should watch this.
Holding a torque wrench at different locations on the handle actually changes the applied torque for length-dependent wrenches.
In short: "torque is torque" doesn't always apply.
Well, there is 13 minutes of my life I wont get back. So, I think I understand the math but the application to real-life is small. His example showed a large difference (relative to the length of the wrench) in the pressure point from the wrench pivot point. If you hold it at the handle the errors will be small
 

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Discussion Starter · #9 ·
So, I think I understand the math but the application to real-life is small. His example showed a large difference (relative to the length of the wrench) in the pressure point from the wrench pivot point. If you hold it at the handle the errors will be small
On the little 1/4" Park wrench if you hold it at the very end of the handle, they show it off ~5%. On a larger wrench with a bigger handle it's probably ~8-10%. Not a big deal in real life unless it's a super critical application. Although, then you shouldn't be using a click style wrench.

The big take away though is... DO NOT choke up on your torque wrench. You could be looking at 50% higher torque.
 

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The big take away though is... DO NOT choke up on your torque wrench.
Why would you even consider doing that though?

This is my issue with so many Youtubers - they take a non-issue and drone on and on about it. Kinda like the "as seen on TV" products that show imbecilles losing fingers trying to open a tin can so they can sell an overpriced can opener.
 

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Discussion Starter · #11 ·
Why would you even consider doing that though?

This is my issue with so many Youtubers - they take a non-issue and drone on and on about it.
It's not a non issue. People use tools incorrectly all the time.
It's not intuitive to some that you can't do that. Some people are just dumb.
Hell... just above a poster here was saying it's FOS.

From a web page about Torque Wrenches.
This is a NO NO!
 

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On the little 1/4" Park wrench if you hold it at the very end of the handle, they show it off ~5%. On a larger wrench with a bigger handle it's probably ~8-10%. Not a big deal in real life unless it's a super critical application. Although, then you shouldn't be using a click style wrench.

The big take away though is... DO NOT choke up on your torque wrench. You could be looking at 50% higher torque.
I've choked up on a baseball bat, I've choked up a cough drop. I've choked up at a sad movie, but I have never choked up on a torque wrench
 

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The big take away though is... DO NOT choke up on your torque wrench. You could be looking at 50% higher torque.
This is really a no-brainer - or should be.
 

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As the guy who actually sends our torque wrenches out for calibration at work, even the calibration company considers ±5% to be acceptable. Of all the tools I have in my inspection lab, these have the greatest acceptable tolerance; if you had a Vernier which could only calibrate to ±5%, you'd scrap it!
 

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torque is simply the cross-product of force and moment-arm. If you change the moment-arm, you change the torque. If you change the force, you change the torque.

A properly calibrated torque wrench measures how much torque is being applied to a bolt. It is not measuring the amount of force you are applying to the wrench. It is not measuring how far out you are holding the wrench. It is measuring the cross-product of the two.
 

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Huge in Japan
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Not if used improperly.
This was proven in the video. Improper use will produce a bolt torque that exceeds the wrench setting.
Be careful, he used the word 'measures' which implies a measuring device which does indeed display what is measured at the area of interaction with the fastener. I can put a rotary force transducer inline with an arm of any length and obtain a proper torque reading. The device in the video is an overload release type of device where the overload releases at a distance from the area of interaction, deriving torque from that load presumes proper use or all bets are off. This presumes of course that Grog McCoy is speaking of the former device rather than the latter. A properly calibrated clicker style device still has to be used in a particular manner to achieve desired results. It can be used in a manner that produces undesirable results in spite of it being properly set.

As the guy who actually sends our torque wrenches out for calibration at work, even the calibration company considers ±5% to be acceptable. Of all the tools I have in my inspection lab, these have the greatest acceptable tolerance; if you had a Vernier which could only calibrate to ±5%, you'd scrap it!
Stop calling calipers verniers.
 

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Russian Troll Farmer
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......
Stop calling calipers verniers.
...but it looks so much more sophisticated on an AS9102 document! Besides, I have a couple of major aerospace companies who will not accept just "calipers" as a tool, since there are different types of calipers. They WILL accept "Vernier calipers" or just "Verniers", so that is the term we use. They also quibble about where the terms "conforms" and "complies" are to be used. I have a 3-page bulletin about THAT fiasco posted on the wall at work....

So, OK, the post LOOKS legit, but then again, I've seen corporations use 'mathematical obfuscation' before to create a bald-ass lie. I remember about a decade ago, a company which made ducted wind turbines which claimed an impossibly efficient power conversion rate, and backed it up with several pages of mathematical "proof".....until somebody noticed that the intake area was only the fan area, not the duct intake area. Suddenly, efficiency went from 'phenomenal' to just 'average', and the company folded about a year later (screwing us, because they hadn't completely paid for their prototype manufacturing yet..).

Anyway, the moral of this story is: always use tools the correct way.
 

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Huge in Japan
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Anyway, the moral of this story is: always use tools the correct way.
Amen to that.

In my now approaching 25 years in metrology as a quality engineer I am so grateful to have avoided the calibration end of things. Calibration is thankless work.
 
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