Man Calibrating Torque Wrench

What is torque wrench calibration?


Thanks for reading our next “What is…” blog post! Today we’re talking about torque wrench calibration. To kick off this subject, let’s start with explaining what a torque wrench is exactly. Torque means a twisting force. This can be applied to a lot of situations in your daily life. A torque wrench is a device which exerts a twisting force on a threaded fastener, to a specific tightness. Torque wrenches are used in a wide range of industries like aviation, offshore, nuclear, (process)industry and maritime industry.

Why does a torque wrench need to be calibrated?

You might think: why is torque wrench calibration so important? This is essential to ensure the continuity of your production process. It doesn’t matter if you’re using a small torque wrench or a bigger one, both must work within strict tolerances to provide the right force to tighten bolts or nuts as required. A properly calibrated wrench will accurately measure torque, allowing a fastener to be tightened with the correct tension and preventing mutual connection failures. An excessive deviation can result in less reliable or vulnerable bolt connections.

How often does a torque wrench need to be calibrated?

Calibrating your torque wrench has to be done at least once a year of after every 5000 cycles, just whichever occurs first. This is necessary to meet ISO 6789 regulations. Modern international standards for torque wrenches are based upon ISO 6789-1:2017 and 6789-2:2017. ISO grants 4% to 6% over or below the torque indicated by a torque wrench’s setting in testing. However, anything outside of those barriers is considered out of compliance. Assessing whether a torque tool is out of calibration requires torque analyzers and sensors.

GMS Instruments torque wrench calibration service.

We are specialized in torque wrench calibration of 20 Nm up to 3150 Nm. Early 2020 we have expanded our torque wrench calibration service by renewing our test bench in partnership with Gedore. By partnering with this company regarding the torque wrench calibration, with every tested and calibrated wrench a test certificate which matches international standards is issued. With the high precision (within ± 1%, ± 1 digit of readable value) Gedore calibration bench, we are the specialist in the calibration of a.o. left and right turning wrenches:

  • Digital Torque Wrenches
  • Hydraulic Torque Wrenches
  • Click Torque Wrenches
  • Electronic Torque Wrenches

This means our calibration and certification are according to ISO 6789 standards.


Have you become curious about how we can help you with calibration your torque wrench(es)? Please contact our experts and we will be more than happy to help!

General contact

Driemanssteeweg 190
3084 CB Rotterdam
The Netherlands