The many well-known bolting insecurities resulted in expensive checkups and re-tightening procedures to become common for high loaded bolts in (steel) constructions such as cranes and wind turbines.

BoltSafe washers measure the actual bolt load during assembly and over time. With a simple test the actual bolt load can now be determined rather than assumed or guessed. This leads to enhanced safety, dependable joints and better control. Cost benefit both during installation and throughout the joint’s service life is improved too.


The BoltSafe technology does not work with strain gauges. It measures the changing of the magnetic field instead. This results in less height of the sensor and a less expensive construction.

As shown in the animation above, the BoltSafe Sensor starts monitoring when the bolt is tightened. Please not that Under Range (UR) does not mean the sensor is broken. UR simply shows the bolt load is not high enough to monitor yet. BoltSafe sensors can monitor in a continuous as well as a periodic manner, these options are explained below.

Continuous measurements

With BoltSafe Continuous Monitoring System (CMS) sensors it is possible to interconnect several sensors into a network. The residual bolt load can be monitored in a continuous manner from one connecting point.

Periodic measurements

BoltSafe Periodic Monitoring System (PMS) sensors have a non-contacting interface and require no cable connections. An inductive interface connected to a handheld instrument poweres the unit during service. The unit is powered over an inductive interface connected to a handheld instrument during service. The BoltSafe Sensor PMS can be read by the handheld instrument SM-200 BoltSafe Reader in combination with a PMS-probe. The user can monitor the residual bolt load directly on the instrument.

At BoltSafe we are commited to providing the total solution. If you cannot find the relevant component part on this site, please do not hesitate to contact us.