Magnetised transducer element for torque or force sensor

A magnetic torque transducer for a structure such as a disc through which torque is transmitted between a central shaft to which the disc is mounted and an outer periphery such as a gear wheel. The intervening region through which torque is transmitted is magnetized to provide a transducer element having two magnetized, annular regions which cooperate to emanate a magnetic field that is torque-dependent. The two magnetized regions may be longitudinally-magnetized through the disc or circumferentially magnetized with opposite polarities. A sensor assembly of non-contacting sensors is used to detect the emanated field and connected in circuitry to provide a torque-dependent signal. In an alternative a single magnetized annular region is employed. The annular region or regions need not be a complete annulus. The same disc-like structure can also be used as force sensor for measuring bending moments or other forces which result in stress occurring in the disc.