Abstract: A strain gauge or a bridge comprising four strain gauges is arranged on a support such that the strain gauge(s) is (are) situated in a neutral zone. The support is secured to the object to be measured on both ends, preferably by means of screws. Between the end portions which are screwed down and the central portion accommodating the strain gauges, the support has a zone of low bending rigidity.The support can be very readily manufactured from a strip of material whose longitudinal sides are flanged so that a U-shaped profile is obtained. Flanges can also be formed only at the centre near the strain gauges, so that the zones of low bending rigidity are automatically formed.The transducer is intended first of all to be fitted on shafts of existing lorries in order to measure the shaft load.