A portable tool includes an electric motor drive, an output body, a detection device, and a transmission device. The output body can be rotated about a predefined axis. The detection device detects at least one physical measured value which is characteristic of the output operation with the output body. The transmission device transmits the physical parameter contactlessly from a rotating region of the tool to a stationary region of the tool. The transmission device includes a rotor coil and a stator coil. The rotor coil rotates with respect to the stator coil. The stator coil is configured without a former in a region between the stator coil and the rotor coil.