Skidmore-Wilhelm bolt testers are very commonly used in the market since the 1950’s, but BoltSafe load cells use a different kind of technology. Our sensors measure the changes in the magnetic field using magnetoelastic technology. This causes BoltSafe load cells to be very compact. They are specially designed to measure and monitor bolt load in bolted joints. The load cells can be used as well during assembly (for calibration and testing), as over time (mounted in a bolted construction). Using our sensors enhances safety, makes joints more dependable and secures control over bolted connections.
The difference with a Skidmore-Wilhelm bolt tester, is that they are used as washers. They are placed on the non-driven side of a bolted connection, preferably under a nut. While the bolt is being tightened, the applied force results in a minor deformation of the BoltSafe washer. The sensor measures the changes in electrical resistance caused by these deformations. This is the data we use to determine the bolt load and tension at any given moment.