The plug connector (1) comprises a pin (2), a helical spring (12) applying a rearward axial force to the pin (2) and a one-piece casing (20) with a closed front section (20a) and a through aperture (21). Behind the front section (20a) there is a side-wall aperture (24) through which the pin (2) fitted with the helical spring (12) can be inserted into the casing (20) from the side. Securing components (25, 26) prevent the pin (2) and/or the helical spring (12) from moving outwards radially from the plugging direction (A).
