Die-casting piston, - having a receiving unit which can be secured to a piston rod, comprising a cooling device and a connection device for the piston rod, - having a hollow-cylindrical carrier member which is constructed in a cup-like manner and which has a melt-side end face, on the covering face of which at least one hollow-cylindrical sliding member can be mounted, wherein a front ring is arranged between the end face of the carrier member and an end face of the sliding member and acts as an end-face first retention element for the at least one hollow-cylindrical sliding member, - in that the carrier member can be mounted on the receiving unit so as to engage axially over the cooling device and can be locked to the receiving unit and released again by means of a connection device, characterised in that - the connection device is arranged at the side facing away from the end face of the carrier member axially after the sliding member, wherein the connection device is a bayonet closure, - in that the at least one hollow-cylindrical sliding member can be fixed at the side facing away from the end face of the carrier member by means of an assembly ring which is configured so as to be torsionally resistant with respect to the carrier member, - in that, at the position of the assembly ring, the outer contour of the carrier member is configured as a polygon and the inner contour of the assembly ring is also configured as a polygon which fits precisely with respect to the outer contour of the carrier member, and - in that the carrier member can be locked with respect to the receiving unit in a torsionally resistant manner by means of at least one fixing element. - having a receiving unit which can be secured to a piston rod, comprising a cooling device and a connection device for the piston rod, - having a hollow-cylindrical carrier member which is constructed in a cup-like manner and which has a melt-side end face, on the covering face of which at least one hollow-cylindrical sliding member can be mounted, wherein a front ring is arranged between the end face of the carrier member and an end face of the sliding member and acts as an end-face first retention element for the at least one hollow-cylindrical sliding member, - in that the carrier member can be mounted on the receiving unit so as to engage axially over the cooling device and can be locked to the receiving unit and released again by means of a connection device, characterised in that - the connection device is arranged at the side facing away from the end face of the carrier member axially after the sliding member, wherein the connection device is a bayonet closure, - in that the at least one hollow-cylindrical sliding member can be fixed at the side facing away from the end face of the carrier member by means of an assembly ring which is configured so as to be torsionally resistant with respect to the carrier member, - in that, at the position of the assembly ring, the outer contour of the carrier member is configured as a polygon and the inner contour of the assembly ring is also configured as a polygon which fits precisely with respect to the outer contour of the carrier member, and - in that the carrier member can be locked with respect to the receiving unit in a torsionally resistant manner by means of at least one fixing element.