An electromechanical power steering unit for a motor vehicle includes an integral component having a torque sensor unit, which detects the rotation of the upper steering shaft relative to the lower steering shaft. The torque sensor unit includes a ring magnet rotationally fixed to the upper steering shaft and a magnetic flux guide connected to the lower steering shaft. A magnet sensor detects the rotation of the shaft connected to the ring magnet with respect to the lower shaft connected to the magnetic flux guide and the ring magnet is carried by a ring magnet sleeve, which sits on the upper steering shaft and is made from a thermoplastic material and is molded by way of ultrasound forming in the upper steering shaft in one region for mounting on the upper steering shaft.