Frequently Asked Questions (FAQ)

What’s the difference between calibrating a torque wrench and checking it?
Calibration is conducted under very controlled conditions using a variety of specialized equipment and highly trained and experienced personnel. Traceability to NIST must be maintained for any and all measurement equipment, including the equipment used to calibrate the measurement equipment. Calibration is carried out in a tightly controlled environment with the actual temperature and humidity recorded to assure compliance with requirements. There is a level of technological rigor involved that is effectively impossible to replicate in vehicle service facilities.

The calibration process includes measuring the tool accuracy in the “as found” condition (as it was received), making any necessary adjustments to the tool, then measuring the accuracy again to verify the effectiveness of the adjustment. These results are automatically recorded, and a certificate of calibration that delineates all the test conditions and test results is generated, stored and printed.

Checking is a process that involves usually a single check of the tool (no adjustment). The check covers more than just the torque output. It includes the condition of the tool and factors that affect its’ suitability for use.

Checking accuracy is not as rigid as calibration. The torque check results will frequently vary from torque calibration results by a small amount due to the uncontrolled environment in which the tools are checked, the lack of specialized equipment and numerous other factors. This is allowed for by giving a slightly wider tolerance to check requirements than to calibration requirements.

The purpose of a check is to make sure the tool has not wandered greatly in its’ accuracy. Checks are not a substitute for calibration but rather an adjunct to it.

Are there other qualified laboratories that can calibrate our torque wrenches and the Tenexes tester?
Yes. In fact, we only calibrate and repair Tenexes brand product, so using a properly-qualified laboratory to perform these services makes a great deal of sense if you have multiple brands of torque wrenches. In addition to being able to handle multiple brands of torque wrenches, these laboratories can often offer very fast service.

“Properly-qualified” in this sense means that the laboratory is ISO 17025 Accredited and that their scope of accreditation includes torque wrench and torque tester calibration. It is possible to be properly accredited yet not qualified in torque wrench and torque tester calibration; expertise in such things as chemical analysis and linear measurement are not applicable.

If you are in need of an independent and appropriately-accredited laboratory for your torque tool and tester calibration, just go to our Links page for assistance in finding one. You may well find that you can increase your process quality and tool availability while simultaneously reducing your calibration costs.

We have multiple shops. What’s the most effective way to handle all of them?
To a large extent this depends upon the geographic spread of the shops. If there are four shops in one large metropolitan area, it may be most cost-effective to place the tester and records in one location and bring the tools to them on a regularly-scheduled basis. If the shops are spread over a large geographic area, it is likely that the best approach is to put one system in each shop.

This system sounds like it makes a lot of sense. Are there other ways to improve the ROI other than those mentioned on the site so far?
Yes. The management guidebook contains additional strategies for improving your ROI, targeted both at fleets and at vehicle maintenance and tire shops.

We are ISO 9000:2000 Registered already. What do we have to do to integrate the Tenexes system to our quality system?
It is likely that a simple change to your policy manual will suffice. The Tenexes system can be incorporated by reference to it in the applicable section of your manual. Something to the effect that: “The Tenexes system will be used for torque management in the wheel installation process.” Since the Tenexes system already includes all of the documents pertinent to training, document control, the training materials and records themselves, the calibration and checking forms, and other items needed to properly manage your process, the incorporation need not address every item individually. Some part of this depends upon how you have structured your system and system documentation, but incorporating the Tenexes system will be fairly straightforward and will also qualify as a bona fide quality system improvement – an ISO 9000:2000 requirement.

The 600 foot-pound tester has a +/- 1% accuracy from 10% to 100% of capacity. Since 250 foot-pound capacity torque wrenches have to be checked at the 20% level, and the 20% level is 50 foot-pounds, can we check them on it?
Yes. As much as we would like to have you purchase two testers instead of one, it really isn’t necessary for tools of 250 foot-pound capacity. The tester may be slightly less than the +/- 1% accuracy at 50 foot-pounds, but we are not calibrating the tools, only checking them. The difference is sufficiently small that the tolerances for checking (in the spreadsheet provided) cover it in their calculations.

Tenexes Div. of Ryeson Corporation
3203 N. Wolf Road • Franklin Park, IL 60131
Phone: 847/260-2050 or 563/249-4170 • Fax: 847/455-0347

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