Power tool attachment part with a torque sensor measuring strain

A power tool attachment part (1) for a power tool, comprising: an elongate housing (3) including an upper housing part (3a) and a lower housing part (3b) interconnected with the upper housing part (1), an input gear wheel (9) configured to be connected to an output shaft of a power wrench, which input gear wheel (9) is arranged at a first end of the housing (3), an output gear wheel (11) with an output connection (11a), which output gear wheel (11) is arranged at a second end of the housing (3), an intermediate gear wheel (13) arranged inside the housing (3) and configured to transmit rotation of the input gear wheel (9) to the output gear wheel (11), a socket (15) arranged concentrically with and radially inside the output gear wheel, and a torque sensor (5) configured to measure the strain on the socket (15) and thereby obtain a measure of the torque at the output gear wheel (11).