Torque Wrench Accuracy ?
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,578
Likes: 36
From: RI
St. Jude Donor '14-'15, '17, '19
Torque Wrench Accuracy ?
I have to remove the wheels from my C6 and know they are supposed to be installed @ 100lbs torque. I am looking at a inevpensive torque wrench accurate within + or - 6%. Is this close enough or is 6% too much of a range. Thanks, Mike
Racer
Joined: Dec 2006
Posts: 340
Likes: 1
From: So. Cal
Most torque wrenches are ±4% in CW direction & ±6% in CCW directions. Most electronic torque wrenches are ±2% in CW direction and ±3% in CCW direction.
If you buy a used torque wrench ask the frequency of use and if/when the last time it was calibrated. I won't recommend a brand because I've seen all popular brands out of tolerance, and looks are deceiving.
I check these things out almost everyday.
If you buy a used torque wrench ask the frequency of use and if/when the last time it was calibrated. I won't recommend a brand because I've seen all popular brands out of tolerance, and looks are deceiving.
I check these things out almost everyday.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Most torque wrenches are ±4% in CW direction & ±6% in CCW directions. Most electronic torque wrenches are ±2% in CW direction and ±3% in CCW direction.
If you buy a used torque wrench ask the frequency of use and if/when the last time it was calibrated. I won't recommend a brand because I've seen all popular brands out of tolerance, and looks are deceiving.
I check these things out almost everyday.
If you buy a used torque wrench ask the frequency of use and if/when the last time it was calibrated. I won't recommend a brand because I've seen all popular brands out of tolerance, and looks are deceiving.
I check these things out almost everyday.
Safety Car
Joined: Jan 2008
Posts: 4,711
Likes: 3
From: Middle of No where AK
I know the us military guys send out the ones we use on aircraft to be calibrated fairly occasionally. I wonder if there is such an agency for the civilian world.
FYI if you ever drop your torque wrench or store it imporperly it greatly increases its chances for inaccuracy.
FYI if you ever drop your torque wrench or store it imporperly it greatly increases its chances for inaccuracy.
Racer
Joined: Dec 2006
Posts: 340
Likes: 1
From: So. Cal
Yes calibration is available to anyone. I'm sure that if you find out what company the military uses, they'll calibrate yours.
Also true if you drop the torque wrench, but it has to be a good drop. The torque wrench should always be stored at or less than 20% of it's full range. Also, torque wrenches are meant to be accurate from 20% - 100% full scale.
Also true if you drop the torque wrench, but it has to be a good drop. The torque wrench should always be stored at or less than 20% of it's full range. Also, torque wrenches are meant to be accurate from 20% - 100% full scale.
Safety Car
Joined: Jan 2006
Posts: 4,598
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From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
See, for example, http://buy1.snapon.com/catalog/item....re&dir=catalog
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Team Owner
Joined: Jun 2005
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
. . . . unless the mechanic is using the proper range Torque STICK, and knows how to use it.
See, for example, http://buy1.snapon.com/catalog/item....re&dir=catalog
See, for example, http://buy1.snapon.com/catalog/item....re&dir=catalog
Safety Car
Joined: Oct 2003
Posts: 3,644
Likes: 13
From: South of Boston MA
Just a couple of other things worth mentioning: Remember to set the torque wrench back to zero foot pounds after using it. It should not be left at the 100 foot pound setting while not in use for long periods of time. I'm talking about the mechanical units. Most of the companies that make torque wrenches (I have an S&K model) offer a calibration service but you have to mail the unit back to them. Lastly, when you torque the wheels remember to torque in a star pattern and don't jerk the wrench down to get to the torque number. Use a steady pressure until you hear the click or beep. Hope this helps. 
Race Director
Joined: Sep 2000
Posts: 11,146
Likes: 1,913
From: Missouri City, TX
My Sears Craftsman instructions say to store at 20 ft-lbs or less. I treat mine like a precision instrument. I store it in its plastic case in my master BR closet in the house so it is not exposed to the heat and humidity of my garage.
Racer
Joined: Jul 2009
Posts: 384
Likes: 2
From: Warrenville IL
Yes calibration is available to anyone. I'm sure that if you find out what company the military uses, they'll calibrate yours.
Also true if you drop the torque wrench, but it has to be a good drop. The torque wrench should always be stored at or less than 20% of it's full range. Also, torque wrenches are meant to be accurate from 20% - 100% full scale.
Also true if you drop the torque wrench, but it has to be a good drop. The torque wrench should always be stored at or less than 20% of it's full range. Also, torque wrenches are meant to be accurate from 20% - 100% full scale.
I read an article about torque settings in Motorcyclist and they said that most, if not all, torque wrenches are inaccurate in the first 20-25% of their range.
Race Director
Joined: Mar 2005
Posts: 10,399
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From: Austin Texas
3/8" to 250 inch pounds.
3/8" to 80 foot pounds.
1/2" to 250 foot pounds.
When I need more than 250 ft #'s my neighbor has a huge 3/4" drive I can borrow.
Racer
Joined: Dec 2006
Posts: 340
Likes: 1
From: So. Cal
They should not be. Industry standard it to verify 20%, 60% & 100% of the full range in CW and CCW direction. So that article is misleading.
Former Vendor
Joined: Feb 2004
Posts: 9,615
Likes: 13
From: Burlington NC
I know the us military guys send out the ones we use on aircraft to be calibrated fairly occasionally. I wonder if there is such an agency for the civilian world.
FYI if you ever drop your torque wrench or store it imporperly it greatly increases its chances for inaccuracy.
FYI if you ever drop your torque wrench or store it imporperly it greatly increases its chances for inaccuracy.
Randy
Race Director
Joined: Sep 2007
Posts: 16,557
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
I've used beam torque wrenches for nearly 50 years without concerns of breakage or calibration. Never had a failure on any part that had a torque spec due to improper tightening either.
