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Published : 09/25/2018 11:57:41

If you own professional torque wrenches, you are probably already in the know about the new calibration standard. In accordance with international regulations, torque wrenches need to be tested and certified every twelve months or every 5000 tightenings. However, in October 2017, the EN ISO 6789:2017 took effect and substituted the previous EN ISO 6789:2003 standard, thus introducing significant changes for both producers and torque tools owners. Lets look at this standard together to better understand what will change and what will have to be done in order to comply with it by October 2018.

EN ISO 6789:2017 regulation


The new standard consists of two parts:

  • The first part is targeted to producers and sets a number of minimum requirements that the torque tools need to meet, as well as establishing specific standard to be held by the documents accompanying the tools.
  • The second part is targeted to test labs that deal with certifications, they have to follow specific criteria to calculate the torque tools uncertainty of measurement. Additionally, torque tools testing is not carried out at 20%, 60%, 100% capacity but at the lowest value of the showed measurement range, at 60% and 100% capacity. This detail allows to check the torque wrench compliance on the whole showed measurement range, not only on a portion of it.

However, as essential as EN ISO 6789:2017 is to test torque tools precision before they enter the market, it also involves a substantial increase of testing time, which vary according to the kind of tool, the kind of plant used for testing, and so on. We are, in fact, talking about more than twice the time necessary to carry out checks and testing: this is why Stahlwille designed and developed TORKMASTER 5, a new software, able to facilitate and speed up this process.


If you are an industrial or a laboratory technician and would like to know more information on the new EN ISO 6789 standard, that will come into force from 17 October 2018, you can sit in the workshop organized by Stahlwille! It will be held at the Hotel Montini in Peschiera Borromeo, in the neighbourhood of Milan, in two sessions to choose from: November 5th from 2:00 pm to 6:00 pm and November 6th from 9:00 am to 1:00 pm.

Stahlwille Workshop EN ISO 6789

You will learn in detail how to achieve the regular calibration of torque tools following the new rules, as well as how to issue the new certifications. To participate, fill out the form at the following link: . Seats are limited and all the requests will be processed and confirmed by the first week of October.


TORKMASTER 5 is available for every client that already owns a manual or motorized test bench, as well as clients who still need to purchase one. It consists of a software that is able to automatically calculate torque tools uncertainty values, drastically cutting testing times. Additionally, a database will be made available for Stahlwille torque tools. This will contain the required values of uncertainty to be followed, calculated by the company using a statistical method. For any other tool brand, you will be able to calculate the statistical values after the tenth time testing the tool and its insert.

Stahlwille software TORKMASTER 5


In Mister Worker™’s catalog you will find different models of Stahlwille test benches, useful for certifying every kind of torque tools from torque screwdrivers to 3000Nm torque wrenches. These are highly professional test benches of extremely high quality, produced in the Stahlwille plants in Germany and subjected to strict quality assurance tests before being allowed to enter the market.


Stahlwille Manutork© Manual test benches are really simple to use, thanks to intuitive management software and manual operating mechanisms which allows you to calibrate, with no physical effort, torque tools up to 3000 Nm.

Stahlwille torque control benches

In Mister Worker™’s catalog you can find the Stahlwille Manutork© 7791 test bench and the Stahlwille Manutork© 7792 test bench. They have mechanical rationing up to 4000 Nm and, thanks to a special force transmitting system, they take the necessary measurements without moving the spot where the force is applied. This way, the torque wrench that is being calibrated  will stay in the same position during the whole process, thus avoiding mistakes in measurement that could be caused by a shift in the place where force is applied. What makes the Stahlwille Manutork© test benches unique is their modular structure: each user can decide how to put it together according to his professional needs.

For example, if you need to personalize your professional test bench with additional modules, in our catalog you will find the Stahlwille 7791-1 test bench extension and the Stahlwille 7791-2 test attachment for torque screwdrivers.

Stahlwille control tool for torque screwdrivers


Stahlwille Perfectcontrol© motorized test benches, IF Design Award winners, allow you to calibrate both couples torque tools and a single one in a completely automated way: this will additionally decrease times and let you avoid any physical effort. Two versions are available: the Stahlwille 7794-2 test bench, ideal to calibrate mechanical and electronic wrenches by torque value verification; the Stahlwille 7794-3 test bench, also suited for angle - not only torque - verification.

The installation of motorized test benches is intuitive and easy to use: all you have to do is positioning the torque wrench to be tested on the bench and then simply recalling it  with the supplied software, which will automatically start the testing and calibration. If you need to calibrate a Stahlwille torque wrench, the software will automatically identify it, additionally reducing testing times.

You can also use additional modules to modify Stahlwille Perfectcontrol© motorized test benches. For example, in Mister Worker™’s catalog you will find Stahlwille torque sensors and Stahlwille lab transducers.

Stahlwille torque sensors are patented tools for torque wrenches calibration and torque screwdrivers calibration: they are highly precise, thanks to the preparation and digitization of the couple directly in the respective sensor. They can be used on their own, but they are often used as an additional component of the calibration system.

The Stahlwille transducer, specific for use in a laboratory, can also be used to calibrate torque wrenches and screwdrivers: it’s equipped with a high quality precision connector, which is self locking and unaffected by transversal forces thanks to a extremely flat structure.

Stahlwille sensors and transducers

If you would like additional information on the new standard for torque wrench calibration, if you need to purchase a new Stahlwille test bench or update your work tools with new Stahlwille torque tools, please do not hesitate to contact us. You can email us at [email protected] outlining the details of your request: our team of experts will get back to you as soon as possible and, if you would like to make a purchase, you will receive a personalized quote that will address your needs.

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