Abstract: A cable lead-in device comprises a nipple (1) which has a thread (3) to be secured in the casing (2) of an apparatus, a grip portion (4) and a through bore (5) for a cable. The nipple has a clamping portion comprising a thread (8) and a number of longitudinal fingers (9) with conical end surfaces (11), and a sealing ring (13) to be clamped around the cable when a nut (6), with an internal thread (7), is tightened on the clamping portion of the nipple. The nut (6) has a conical surface (12) for cooperating with the fingers (9), and a locking part (14) surrounding the cable and directed obliquely inwardly, both radially and axially, towards the cable and the fingers (9), respectively. The locking part (14) is so disposed that it will be moved or turned axially outwards into a position in which it tightly engages the cable when the nut (6) is tightened.