- In-house engineering and production
- Short lead times
- Worldwide delivery
- More than 20 years of experience
Uncertainty in bolt load? Use a smart washer!
One of the biggest challenges in bolted connections is the inability to verify if the correct bolt load has been achieved or maintained. Unequal or insufficient bolt load is the most common reason for gasket joints to fail, often resulting in costly leaks. To compensate, gaskets are frequently overloaded during assembly, particularly when using hydraulic tensioners. However, it’s nearly impossible to predict how bolt tension will relax over time.
Other common issues include:
- Bolt fatigue and breakage
- Bolts loosening over time
- Unnecessary and expensive maintenance inspections
- Unknown tool settings or incorrect preload values
These problems are especially critical in high-load structures such as cranes, wind turbines, and industrial machinery, where reliability is essential and check-ups are frequent. That’s the challenge BoltSafe set out to solve: with a smart washer. a bolt load cell that doubles as a washer. By installing this load sensor during assembly, the exact bolt load can be measured in real time and optimized with confidence.
The benefits of BoltSafe smart washers
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Our compact smart washers utilize magnetoelastic technology, offering a more cost-effective solution compared to many other available systems.
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The bolt load is measured across the washer’s entire surface, instead of using just a few pressure points.
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Calibration takes place internally within the smart washer, eliminating the need for calibration at the readout device.
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BoltSafe sensors transmit purely digital signals and are suitable for a wide range of loads, from 18 kN up to 3000 kN.
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Our products are stable over time, with virtually no drift or creep. After factory calibration, they maintain a maximum deviation of just 1% of full scale.
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With an IP66 rating, the sensors are fully protected against dust and resistant to water ingress.
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We provide multiple readout methods to accommodate different needs and use cases.
Bolt load cells
Readout methods
What is a smart washer?
A washer is a machine component which is used in conjunction with a screw fastener such as a bolt and a nut. It is mostly used to keep the screw from loosening or to distribute the load from the nut or bolt head over a larger area. Our smart washer is a special kind of washer, which is able to measure the bolt load on the washer. Therefore, our smart washer is a specific kind of load sensor, shaped as a washer. It is the perfect solution for measuring bolt load! It replaces traditional washers and adds intelligence to your bolted assembly, without changing your standard bolting procedures.
Our smart washers are able to measure load very accurately and are therefore widely used in many industries. Initially they are force transducers that convert force into electrical signals, that can then be measured and standardized. Because of this conversion, data can be read and recorded by users. There are a few types in the market that are using different technologies, such as strain gauges or piezoelectric technology. BoltSafe smart washers use magnetoelastic technology. With this technology, the changes in the magnetic field are measured.
By knowing the exact bolt load:
- You improve operational safety
- Gain full control over structural integrity
- Extend the service life of critical connections
- Gain early detection of overload, underload, and bolt relaxation
- Reduced or eliminated need for re-tightening
- Have lower maintenance costs and fewer inspections
Contact us for more information or to order our smart washers
How does the BoltSafe smart washer work?
BoltSafe smart washers are engineered to accurately measure and monitor bolt load in bolted assemblies, both during initial installation and throughout the service life. This precise measurement capability contributes to improved safety. By knowing the exact bolt tension, the reliability of the joint increases, offering greater control over structural integrity.
To use, position the BoltSafe smart washer on the passive (non-driven) side of the connection, ideally beneath the nut. As the bolt is tightened, the washer undergoes slight deformation due to the applied force. This deformation alters the washer’s electrical resistance, which can then be recorded. These resistance changes allow us to determine the bolt load with high precision at any time.
BoltSafe smart washers are used for many applications and in many industries. With our sensors, you eliminate the guesswork from bolt tightening. Whether during assembly or in-service monitoring, you gain precise insight into bolt load – enhancing reliability, reducing downtime, and improving safety across your operations.
Are you interested in using or distributing our smart washers? Please contact us through info@boltsafe.com or call us at +31246790797. If you have any questions about the functionality, usability or applicability of our products, do not hesitate to contact us.