Boss told me today that from what he’s been told, torque wrenches need to be sent away regularly for calibration. I’ve never heard this. We use wheel bar for tightening wheelnuts and the independant fitter we use checks torque when doing inspections/repairs etc.
Is this “rule” real or just a DCPC time-filler?
Apparently a torque wrench has to be callibrated onece a year and the certificate held in the office .
not sure how true or not that claim is but I did hear that last weekend on a "training day " so it must be true mustn’t it ?
Once a year calibration on a torque wrench if your gonna use it.
I’m not aware of any official rule. Obviously you do in a commercial workshop environment get torque wrenches calibrated, at a set schedule, to ensure accuracy. The same way roller brake testers are done and vehicle lifts inspected.
If it’s just for drivers to check with in the yard I’m not sure it’s worth bothering. Best practice is to always wind off a torque wrench when you’ve finished using it to help maintain accuracy.
I’m not a fan but, for drivers wheelnut checking, you could probably get a preset wrench from someone like Norbar that had minimal need for calibration or maintenance. Wheel nut indicators are a better solution to readily checking if anything has moved as part of daily checks.
Edit to add:
Interestingly, Norbar themselves recommend not winding back and suggest if you leave the wrench at a set torque recalibration requirements should be minimal.
Should I wind my Torque Wrench Back to Zero?
One very important consideration for recalibration is how you set you torque wrench after use. Anyone working in torque will have been taught to wind their torque wrench back to zero after every use. However, this is wrong. Certainly if the wrench is wound back at all it should not be adjusted below the minimum scale marking (usually 20% of maximum) – never to zero as this can adversely affect the calibration of the wrench.
We have thousands of Production Type wrenches in service that are left at their setting for months on end without a problem. Other factors in the way that torque wrenches are used and sometimes abused will have a far greater influence on calibration and the final torque delivered to the fastener than whether the wrench is left ‘wound up’.
We need to keep records on every wheel that’s removed and who’s removed it. So this calibration talk doesn’t surprise me.
Main issue with preset torque wrenches… always wind them back off after use, ( torque & click type ) or the spring in the bar gets weak.
Many on here who’ve done cylinder head gaskets repairs know the torque and angle principle… that was the best thing about the flexy bar wrench.
TORQUE:- ( count down ) 
.The case of ’ Perterm vs Bking ’
So, wheelbar with a short piece of scaffold tube is the way to go then?
Torque wrenches should be maintained and callibrated, cant remember the official time scale through.
And as merc say’s records should also be kept every time a wheel is fitted and every time the wheelnut torque is rechecked.
This info was given to our place at compliance audit last year.
When ever the boss try’s ■■■■ like this with me, “I’m not a mechanic, get someone else to do it!”
All our personal and workshop torque wrenches ,mutimeters gauge etc are done every 6 months
simon1958:
Main issue with preset torque wrenches… always wind them back off after use, ( torque & click type ) or the spring in the bar gets weak.
Many on here who’ve done cylinder head gaskets repairs know the torque and angle principle… that was the best thing about the flexy bar wrench.TORQUE:- ( count down )
I don’t remember that. Mind you, the old noggin ain’t what it used to be. 
Muckaway:
So, wheelbar with a short piece of scaffold tube is the way to go then?
wrax them nuts up till they crack 3 times…no drama.
Own Account Driver:
I’m not aware of any official rule. Obviously you do in a commercial workshop environment get torque wrenches calibrated, at a set schedule, to ensure accuracy. The same way roller brake testers are done and vehicle lifts inspected.If it’s just for drivers to check with in the yard I’m not sure it’s worth bothering. Best practice is to always wind off a torque wrench when you’ve finished using it to help maintain accuracy.
I’m not a fan but, for drivers wheelnut checking, you could probably get a preset wrench from someone like Norbar that had minimal need for calibration or maintenance. Wheel nut indicators are a better solution to readily checking if anything has moved as part of daily checks.
Edit to add:
Interestingly, Norbar themselves recommend not winding back and suggest if you leave the wrench at a set torque recalibration requirements should be minimal.Should I wind my Torque Wrench Back to Zero?
One very important consideration for recalibration is how you set you torque wrench after use. Anyone working in torque will have been taught to wind their torque wrench back to zero after every use. However, this is wrong. Certainly if the wrench is wound back at all it should not be adjusted below the minimum scale marking (usually 20% of maximum) – never to zero as this can adversely affect the calibration of the wrench.
We have thousands of Production Type wrenches in service that are left at their setting for months on end without a problem. Other factors in the way that torque wrenches are used and sometimes abused will have a far greater influence on calibration and the final torque delivered to the fastener than whether the wrench is left ‘wound up’.
Have just had a look at the instructions for my Draper mini torque wrench and it says, Quote word for word -
“When the torque wrench is not in use, ensure adjustment at the lowest torque setting”
I take it that means wind it back to zero, but it is not the best of English!
I see it also has a test certificate dated 2010 and sys it should be calibrated every 12 months.
I do also have a bigger torque wrench that could be 30 year old, and I tested that myself a year or two ago with a long bar and a bucket of water and it seemed reasonably accurate. (maybe returning 75lb ft when set at 80) near enough for pit work!
spent 30 yrs in engineering ,22 of them in heavy engineering . torque wrenches were set (calibrated) to a guage on the wall to the required setting before every use . the scale on the wrench was ignored .which made the fact that quality control dept (that’s inspection dept to us old uns ) collected them up on a regular basis and calibrated them then stuck a official looking sticker on them to say they had , was a bit of a farce . but it kept the pc / h+s brigade happy . at the end of the day just go with the flow as for do we release the tension or not? I was taught as a apprentice to wind it back every time . so that’s what I did .
I’ve always wound them back too.
Bluey Circles:
Own Account Driver:
I’m not aware of any official rule. Obviously you do in a commercial workshop environment get torque wrenches calibrated, at a set schedule, to ensure accuracy. The same way roller brake testers are done and vehicle lifts inspected.If it’s just for drivers to check with in the yard I’m not sure it’s worth bothering. Best practice is to always wind off a torque wrench when you’ve finished using it to help maintain accuracy.
I’m not a fan but, for drivers wheelnut checking, you could probably get a preset wrench from someone like Norbar that had minimal need for calibration or maintenance. Wheel nut indicators are a better solution to readily checking if anything has moved as part of daily checks.
Edit to add:
Interestingly, Norbar themselves recommend not winding back and suggest if you leave the wrench at a set torque recalibration requirements should be minimal.Should I wind my Torque Wrench Back to Zero?
One very important consideration for recalibration is how you set you torque wrench after use. Anyone working in torque will have been taught to wind their torque wrench back to zero after every use. However, this is wrong. Certainly if the wrench is wound back at all it should not be adjusted below the minimum scale marking (usually 20% of maximum) – never to zero as this can adversely affect the calibration of the wrench.
We have thousands of Production Type wrenches in service that are left at their setting for months on end without a problem. Other factors in the way that torque wrenches are used and sometimes abused will have a far greater influence on calibration and the final torque delivered to the fastener than whether the wrench is left ‘wound up’.
Have just had a look at the instructions for my Draper mini torque wrench and it says, Quote word for word -
“When the torque wrench is not in use, ensure adjustment at the lowest torque setting”I take it that means wind it back to zero, but it is not the best of English!
I see it also has a test certificate dated 2010 and sys it should be calibrated every 12 months.I do also have a bigger torque wrench that could be 30 year old, and I tested that myself a year or two ago with a long bar and a bucket of water and it seemed reasonably accurate. (maybe returning 75lb ft when set at 80) near enough for pit work!
It shouldn’t need calibrating if it’s not been used. The calibration requirement is based on so many applications, usually in the thousands. Because no-one could be arsed to record how many times it’s been used between calibrations you end up with time periods based on averages.
For home use doing the odd engine rebuild, that type of thing, I would honestly doubt there’s ever any real need to get one calibrated if it was bought new. Even then most automotive applications will be fairly forgiving to a degree of inaccuracy when torqueing up. It’s applications like aviation where it’s safety critical to have the accuracy. Having said that I did lend one of mine to someone, I knew, who worked on Boeing jets once and he didn’t seem bothered I wasn’t sure when it was last calibrated.
Anyone who’s used them in their working life get’s winding them back to zero drummed into them before they’ve even picked one up. That and the other one of not using them to bust loose stuff. Norbar seems to be saying both of those don’t matter nearly as much as conventional wisdom suggests.
If the recommendation is for them not to be wound back to zero then why are they always on zero when you take a brand new one out of the box? Dial type gauges return to zero automatically.
I was taught that torque wrenches should be wound back to ZERO when not in use.
Recommendations are that for drivers checking wheel nuts they should use a bar and socket with the bar no longer than 20 inches. If the wheel nut moves with the 20" bar, report it to a mechanic.
A common cause of wheelnut/stud failure is overtightenung by people using bars with tubes on the end. Most wheelnuts can easily be tightened more than the specified torque A and that causes stud stretch and eventually failure.
shep532:
I was taught that torque wrenches should be wound back to ZERO when not in use.Recommendations are that for drivers checking wheel nuts they should use a bar and socket with the bar no longer than 20 inches. If the wheel nut moves with the 20" bar, report it to a mechanic.
A common cause of wheelnut/stud failure is overtightenung by people using bars with tubes on the end. Most wheelnuts can easily be tightened more than the specified torque A and that causes stud stretch and eventually failure.
Spot on shep especially the over tightening …If every 6 weeks you torque a wheelnut and add the little bit extra everyone adds ,eventually a stud will fail through stretch …I can’t speak for other manufacturers ,though with DAF the torque setting for a wheel on an XF for example is 700nm…If the wheel has not been removed DAF have a inspection torque which would be 595nm…Someone way more intelligent than me came up with that figure …Is that the true torque and the 700nm is in the studs range I do not know
One little Hitler type stuck up a notice at the fuel stand ( in red ) IT IS A LEGAL REQUIREMENT THAT ALL DRIVER’S TORQUE THEIR VEHICLES WHEEL NUTS WEEKLY. A driver I knew worked there got stopped at a check point and asked if that was true.‘’ Definitley Not’'!! was not the reply. Same reason. Stains the studs.