A magnetic transducer element (22) is formed by rotating an integral region of a shaft (20) about an axis (A--A) in the presence of a magnetic source (30). An annulus (42) of magnetisation results in having its magnetisation in the axial direction. The exterior magnetic field (40) emanated by the annulus (42) exhibits respective axial magnetic profiles of its axially and radially directed components (FIGS. 7 and 8) which have an axial shift under torque. The direction of profile shift depends on the rotational direction of the shaft (20) while magnetisation proceeds. A pair of regions (122a, 122b: 242, 244) exhibiting opposite shift directions provide signals in which torque-dependent shift is separated from axial displacements of the shaft (FIG. 22, FIG. 24). An annulus (42) of magnetisation may be non-uniform with angle about the shaft axis. Measures to prevent eddy currents generated in the rotating region of the shaft under magnetisation are disclosed as are "sweet spots" (230) for sensor placement (FIG. 30) to mitigate non-uniformity effects.