Torque Wrench Calibration/Verification

Could use a hand here. I’ve read several threads regarding “torque wrench calibration” yet I’m still confused. I hope that you all can provide some guidance.
We use torque wrenches while building our electromechanical assemblies. Screws/nuts/bolts into fabricated frames, etc.
The majority of assemblies we build do not have torque specifications called out on the drawings or customer-supplied instructions. We use the torque wrenches primarily as a production aid to help our assemblers properly tighten components.

In terms of Calibration/Verification, our torque wrenches are “verify at use” with a torque analyzer (which is calibrated by the manufacturer annually). In our recertification audit we ran into a minor nonconformance because we do not keep records of calibration/verification (for other items, not just the torque wrenches). We’re clear on how to correct this on our other items, but not for torque wrenches. Do we have to include calibration status for our torque wrenches even though we set them against calibrated equipment before every use?

If you do not have a torque requirement, change the device to 'calibration not required'. What your saying is that calibration is performed 'at use' and that would require some type of verification.

If the device does not need calibration, remove the requirement.

Your auditor is incorrect and your process - as described - is good. Your torque mastering device is what gives the results for each torque wrench, and that should be sufficient record. Your auditor is grasping at straws...

Happy to know the process is good but I don't disagree with the finding. The torque wrenches were listed as examples of evidence, along with our pin & block gage sets and our CMM. The checks are done each time the item is used but we do not record the verification.

9001:2008 7.6 states "Records of the results of calibration and verification shall be maintained"

So if the item is listed in the Calibration Log as "verify at use" but there is no record of the item actually being verified at use, wouldn't that be a missing requirement?

Perhaps I'm looking at the requirement incorrectly?

With regard to the check made before each use - is it a verification against a single setting? Does the wrench get subjected to an annual (or other periodic) calibration that ensures accuracy over the working range of the device?

Now that I think about it, you didn't mention if those wrenches are adjustable or fixed.

In my opinion, if you are using torque wrenches and you have determined the need to verify them before each use (which is, in fact, a much more aggressive and demanding check frequency than a periodic check), you need to show a record of the results, as defined in the standard.

AshleyE said:

Could use a hand here. I?ve read several threads regarding ?torque wrench calibration? yet I?m still confused. I hope that you all can provide some guidance.
We use torque wrenches while building our electromechanical assemblies. Screws/nuts/bolts into fabricated frames, etc.
The majority of assemblies we build do not have torque specifications called out on the drawings or customer-supplied instructions. We use the torque wrenches primarily as a production aid to help our assemblers properly tighten components.

In terms of Calibration/Verification, our torque wrenches are ?verify at use? with a torque analyzer (which is calibrated by the manufacturer annually). In our recertification audit we ran into a minor nonconformance because we do not keep records of calibration/verification (for other items, not just the torque wrenches). We?re clear on how to correct this on our other items, but not for torque wrenches. Do we have to include calibration status for our torque wrenches even though we set them against calibrated equipment before every use?

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Your procedure is to "verify at use". So what evidence/records do you have that this is done?

What does verify at use mean?

AndyN said:

Your auditor is incorrect and your process - as described - is good. Your torque mastering device is what gives the results for each torque wrench, and that should be sufficient record. Your auditor is grasping at straws...

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I disagree. There is no evidence / record of "verify at use".

Torque wrenches are NOT test and measurement equipment. No records are necessary, directly from them (under 7.6 anyways). The record is derived from the actual measuring device the torque mater. Torque drivers are a process and, as such, should be subject to a capability study - which would provide much more useful records of process capability and, hence control. It's more important to know how capable they are of achieving a torque value than all the records maintained at odd points in time. Believe me on this one - I have experience here...

AndyN said:

Torque wrenches are NOT test and measurement equipment. No records are necessary, directly from them (under 7.6 anyways). The record is derived from the actual measuring device the torque mater. Torque drivers are a process and, as such, should be subject to a capability study - which would provide much more useful records of process capability and, hence control. It's more important to know how capable they are of achieving a torque value than all the records maintained at odd points in time. Believe me on this one - I have experience here...

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They truly are measuring tools.

However, it should be stressed, as someone else mentioned, that they may not need calibration in this example.

It all goes back to what the auditor left our in his citation, and should be memorized by EVERYONE that is responsible for calibration.

"Where necessary to ensure valid results . . . "

If it is necessary for valid results, such as when there is a torque spec, they need to be calibrated. If it is not necessary for valid results, THEY DON'T NEED TO BE CALIBRATED.

Where the spec comes from, the customer or the organization doesn't matter.

When you answer the question "When necessary to ensure valid results . . . " you can answer the question as to if calibration is needed or not.

I agree that checking torque calibration daily is way overkill. If that is how you choose to do it, though, you need to keep a record of it.

Big Jim said:

They truly are measuring tools.

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What type of torque are they measuring? Static or dynamic?