The invention relates to a screw nut (1) with a sensor module (5) for determining a pretensioning force of a screw connection, wherein the sensor module (5) comprises at least one deformation detection sensor (7) arranged on a base body (6) of the screw nut (1) for detecting a deformation of the base body (6) of the screw nut (1) and an RFID transponder unit (8), and wherein a printed circuit board (9) of the sensor module (5), on which an antenna (10) of the RFID transponder unit (8) and an electronic circuit of the sensor module (5) are formed and which is electrically conductively coupled to the at least one deformation detection sensor (7), is arranged on an end face (11) of the base body (6). Furthermore, the invention relates to a mounting device (2).