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"Quality ensures long-term success" - the employees of Ernst Berger & Söhne JUWEL-Schraubtechnik GmbH have been following this maxim for over 40 years. After Ernst Berger founded the company with his two sons in the 1980s, the aim was to make a name for himself as an expert in exact and dimensionally accurate contract manufacturing. But quality cannot just be dictated; it has to be lived, and that by every person within a company. Ernst Berger himself was therefore primarily responsible for ensuring the quality of a company until he was 80 years old. 

Today, the
JUWEL brand is positioned as a manufacturer of torque wrenches designed for maximum durability and reliability. Torque wrenches from the 1990s that are still being sent to us for calibration in 2023 prove our claim right.

In the 1990s, we decided to go one step further: With the introduction of the DIN ISO 9001 certification, we faced the quality inspection by an external and independent organisation (TÜV Rheinland). Since then, the
JUWEL quality management system has been audited annually and constantly monitored by the quality representative.

What do we do to meet our high quality standards for you?


We manufacture all mechanical components of the gearboxes ourselves - why do we do this? The quality of a nut runner stands and falls with the quality of the gearbox. We consider the gearing to be an art and the passion of our company - especially because it was Ernst Berger's passion. The other gear components, such as the housings or drive bodies, are also manufactured on modern Hedelius and DMG CNC machines. But let's take a step back:

  • It all starts with a piece of metal - we are grateful to be able to rely on local suppliers who are located within a 50 km radius of our company and have been by our side for over 40 years. Our partners stand for the exact chemical composition of the materials.

  • Once the material has made it to the respective workstation as a rough cut, a programme written in-house by the design department waits for it. The aim is to process the materials gently and without distortions in the component. This is permanently checked and documented by good and bad part calibres. If, contrary to expectations, deviations occur, these components are declared as rejects and documented with an error description for continuous learning effects.

Heat and surface treatment

In the early years, we carried out all of our work in-house, but today we can rely on trustworthy partners who do all heat and surface treatments for us. If you want to offer the best possible quality, it is also necessary to recognise which processes do not represent the core competence of a company. Our suppliers always have their eyes and ears close to the market and current developments in order to make finishing processes even more efficient and better.

  • All components that undergo heat treatment are personally handed over to our supplier. The associated drawing including target hardness leaves no questions in order to obtain the desired result. After the completion report, we receive the treated parts including the quality protocol.

  • All parts that are subjected to surface treatments are manually inspected by our experienced assembly team upon receipt of the goods. This involves a visual inspection as well as a technical check of the dimensions and the surface.


Probably the most beautiful moment for any technology enthusiast is the marriage of all the individual parts to form a tooth-into-tooth, harmoniously working device. In our case, a new torque wrench is created from a multitude of gear wheels and other gear parts. In the process, we rely on a team of experienced, long-standing employees and a young generation with an interest in technology. Detailed exploded drawings and assembly instructions exist for every torque wrench - this guarantees that no component is forgotten and every customer receives a fully functional and reliable tool. Before the nut runners are assembled, all components are selected from our stock and arranged at the assembly site. A final inspection of all parts completes the quality check.

Every torque multiplier that leaves our company is given a unique serial number and is built by one employee. The completion of each assembly is sustainably documented and allows us to transparently and quickly trace possible errors.

Repair and calibration

However, should something go wrong during use or natural wear and tear require the torque wrench to be inspected, then simply send your power wrench to us. Every torque wrench that arrives will be inspected in detail by our experienced team and checked for any malfunctions. A technical report is then written and sent to you transparently, including a cost estimate. With us, there are no hidden costs or incomprehensible repair services. Our technical team is always available for a detailed and comprehensible explanation.

Our calibration certificates are valid for one year. Of course, not every customer uses his torque wrench with the same frequency and intensity. Nevertheless, we recommend keeping to the annual rhythm for the most accurate work possible. If you are not sure whether a new calibration is necessary, please feel free to call us - we will be happy to answer your questions.

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