Torque wrench + extension + socket ??
#1
Torque wrench + extension + socket ??
I was wondering if using an extension with a torque wrench reduces the accuracy of the torque wrench itself. The extension i bought is about 10 inches or so. I bought one that long cause i need one long enough to clear my fender to reach the lug nuts for my spacers.
Will the extension affect the accuracy by a great amount ??
thanks
Will the extension affect the accuracy by a great amount ??
thanks
#7
Metatron
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Common myth that an extension will change the overall torque.
Even if you used a (theoretical) extension made of rubber, that twisted half a turn as you wound it up - the torque wrench would still 'click' at the exact correct torque at the other end.
Counterintuitive, no?
Even if you used a (theoretical) extension made of rubber, that twisted half a turn as you wound it up - the torque wrench would still 'click' at the exact correct torque at the other end.
Counterintuitive, no?
#8
Torque = Force x (perpendicular)distance. The extension doesn't matter. It's the length of where you apply the force that can help or hurt your torque. That's why we use long cheater bars to break loose a tight bolt, nut, etc. Using the same force, you increased the torque with a longer handle.
Wow, I just used my engineering degree!!
Wow, I just used my engineering degree!!
#10
05 RX8 Sold///05 Evo VIII
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Um, yes it does change it.
We (Lexus) just recently(well 3-4 months old) released a fuel pressure sensor torque recall. In the instructions they want you to measure from the end of your particular torque wrench to yield the ideal torque spec since it's critical for gasoline not to leak in the engine bay.
The difference in correlation to length vs torque was 1-8" varied between 2-10ft. lbs.
Point in case, there are many times at work I can't break something loose with my impact...until i use a smaller extension. Think of the energy required to transfer torque across a 100ft driveshaft VS. a 1 foot driveshaft. That's relativity.
We (Lexus) just recently(well 3-4 months old) released a fuel pressure sensor torque recall. In the instructions they want you to measure from the end of your particular torque wrench to yield the ideal torque spec since it's critical for gasoline not to leak in the engine bay.
The difference in correlation to length vs torque was 1-8" varied between 2-10ft. lbs.
Point in case, there are many times at work I can't break something loose with my impact...until i use a smaller extension. Think of the energy required to transfer torque across a 100ft driveshaft VS. a 1 foot driveshaft. That's relativity.
#12
05 RX8 Sold///05 Evo VIII
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Here, end the myth.
Torque your lug nut to 80ftlbs with the longest possible extension you have.
Now torque it with the shortest socket you have.
If it moves with the short one - it's under-torqued and thus inaccurate.
Torque your lug nut to 80ftlbs with the longest possible extension you have.
Now torque it with the shortest socket you have.
If it moves with the short one - it's under-torqued and thus inaccurate.
#13
Registered
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Torque does change if you use the extension on the socket. They have a whole formula for it. Now the length of the wrench it's self or the extension on it doesn't really matter just gives you more leverage. We had one in the squadron for wing bolts that was huge over six foot long and 1200 or 1500 foot pounds.
#14
no agenda
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Great read
Sub'd to an interesting topic.
Call in the Myth Busters I SAY!
Edit: Found this on the interwebz
http://www.freeinfostuff.com/TorqueE...eExtension.htm
I have no opinion on this topic .... just finding the topic interesting .... hanging around to see if we can come to a conclusion ...
Sub'd to an interesting topic.
Call in the Myth Busters I SAY!
Edit: Found this on the interwebz
http://www.freeinfostuff.com/TorqueE...eExtension.htm
I have no opinion on this topic .... just finding the topic interesting .... hanging around to see if we can come to a conclusion ...
Last edited by wcs; 08-16-2011 at 06:44 AM.
#16
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This is definitely very interesting. I would argue that the wrench itself stays accurate, in that it will indicate the amount of torque at the point where the extension (or socket, or whatever) actually mates with the wrench itself. I do NOT think that it would be an accurate measure of the amount of torque that is being applied at the end of the extension, which is really what you would be curious about. Now, that being said, I'm sure it's a miniscule amount, especially when using something like a 10 inch extension, but let's say that extension was 100 feet long, it would take a LOT of torque to spin a 100 foot long bar, and the amount of torque applied at the end of that bar would not be the same as it is at the wrench.
I'm just a silly computer engineer not a mechanical engineer so I could be off there, but that's what I think is happening.
I'm just a silly computer engineer not a mechanical engineer so I could be off there, but that's what I think is happening.
#17
Registered Zoom Zoomer
iTrader: (2)
The torque wrench may click when it has "satisfied" it's [rotational force] setpoint, but the longer the extension the less torque that has actually been applied to the nut (regrets also to our young mechanical engineer who was correct in his cited context, but not in answering the OP's question).
Common myth that an extension will change the overall torque.
Even if you used a (theoretical) extension made of rubber, that twisted half a turn as you wound it up - the torque wrench would still 'click' at the exact correct torque at the other end.
Counterintuitive, no?
Even if you used a (theoretical) extension made of rubber, that twisted half a turn as you wound it up - the torque wrench would still 'click' at the exact correct torque at the other end.
Counterintuitive, no?
#18
Haha thanks for the responses guys.
Alright so lets say i set my wrench to 100 pounds ... What is the actual torque applied on the lug nuts considering im using the 10 inch extension. I doubt itll be more than a 10 pound difference less at the end
. Whats the formula ??
Alright so lets say i set my wrench to 100 pounds ... What is the actual torque applied on the lug nuts considering im using the 10 inch extension. I doubt itll be more than a 10 pound difference less at the end
![Dunno](https://www.rx8club.com/images/smilies/dunno.gif)
#19
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this actually probably becomes a materials science question (I know there is a mat. sci. guy or gal lurking around here somewhere) because the metal that you are using probably has an impact on the "formula" - but honestly, just set the wrench to 100 ft-lb and you'll be fine.
#21
Registered
Great read
Sub'd to an interesting topic.
Call in the Myth Busters I SAY!
Edit: Found this on the interwebz
http://www.freeinfostuff.com/TorqueE...eExtension.htm
I have no opinion on this topic .... just finding the topic interesting .... hanging around to see if we can come to a conclusion ...
Sub'd to an interesting topic.
Call in the Myth Busters I SAY!
Edit: Found this on the interwebz
http://www.freeinfostuff.com/TorqueE...eExtension.htm
I have no opinion on this topic .... just finding the topic interesting .... hanging around to see if we can come to a conclusion ...
#22
Registered
Rotary-RX8, you need to clarify the type of extension you're referring to.
If it's a socket extension for your torque wrench, it won't affect torque.
If it's an extension to lengthen the torque wrench itself, then it will affect torque readings.
If it's a socket extension for your torque wrench, it won't affect torque.
If it's an extension to lengthen the torque wrench itself, then it will affect torque readings.
#23
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#24
SARX Legend
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![TX](https://www.rx8club.com/images/icons/tx.jpg)
UM, there is a TSB that ups the recommended torque specs to 108ft/lb. So you RTFTSB
![Lol](https://www.rx8club.com/images/smilies/lol.gif)
http://www.finishlineperformance.com...2-04-1301b.pdf
#25
Registered
I was wondering if using an extension with a torque wrench reduces the accuracy of the torque wrench itself. The extension i bought is about 10 inches or so. I bought one that long cause i need one long enough to clear my fender to reach the lug nuts for my spacers.
Will the extension affect the accuracy by a great amount ??
thanks
Will the extension affect the accuracy by a great amount ??
thanks
Anything that displaces the point of rotation from the lever that you are using would change the torque reading, unless it is linear to the axis of rotation.
Last edited by Rote8; 08-16-2011 at 11:16 AM.