A one-part piston for an internal combustion engine, comprising: - a piston crown; - two pin boss supports (9, 9'), integrally formed on the piston crown, for a respective pin boss (11, 11'), wherein the pin boss supports (9, 9') and the end faces of the pin bosses (11, 11') are recessed with respect to the radially outer edge of the piston crown in the direction of the piston longitudinal axis; - two skirt elements (14, 14') that connect the pin bosses (11, 11') and that are connected to the piston crown by way of a respective skirt connection (10, 10'), wherein recesses are formed into the shaft connections (10, 10') between the skirt elements (14, 14') and the piston crown; an annular cooling channel, which is disposed in the edge region of the piston crown and the radially outer delimitation of which is formed by a ring wall integrally formed on the piston crown, and the radially inner delimitation of which is formed partly by the pin boss supports (9, 9') and partly by the skirt connections (10, 10'); and - a peripheral projection that is partly integrally formed on the pin boss supports (9, 9') and partly on the skirt connections (10, 10') and has a nose-shaped cross-section, characterized in that - the cooling channel is closed by a substantially cylindrical, one-part ring having an axially oriented continuous gap and a peripheral collar disposed on the outside thereof, the collar forming a detent connection together with a peripheral groove formed into the inside of the ring wall, the ring being seated on the projection, - wherein an axially oriented borehole is introduced into one of the skirt connections (14, 14'), into the borehole an oil feed pipe being insertible, which with the upper part thereof opens into the cooling channel in the region of the ring, and the ring ends (29, 30) of the ring being seated on the upper part of the oil feed pipe. - a piston crown; - two pin boss supports (9, 9'), integrally formed on the piston crown, for a respective pin boss (11, 11'), wherein the pin boss supports (9, 9') and the end faces of the pin bosses (11, 11') are recessed with respect to the radially outer edge of the piston crown in the direction of the piston longitudinal axis; - two skirt elements (14, 14') that connect the pin bosses (11, 11') and that are connected to the piston crown by way of a respective skirt connection (10, 10'), wherein recesses are formed into the shaft connections (10, 10') between the skirt elements (14, 14') and the piston crown; an annular cooling channel, which is disposed in the edge region of the piston crown and the radially outer delimitation of which is formed by a ring wall integrally formed on the piston crown, and the radially inner delimitation of which is formed partly by the pin boss supports (9, 9') and partly by the skirt connections (10, 10'); and - a peripheral projection that is partly integrally formed on the pin boss supports (9, 9') and partly on the skirt connections (10, 10') and has a nose-shaped cross-section, - the cooling channel is closed by a substantially cylindrical, one-part ring having an axially oriented continuous gap and a peripheral collar disposed on the outside thereof, the collar forming a detent connection together with a peripheral groove formed into the inside of the ring wall, the ring being seated on the projection, - wherein an axially oriented borehole is introduced into one of the skirt connections (14, 14'), into the borehole an oil feed pipe being insertible, which with the upper part thereof opens into the cooling channel in the region of the ring, and the ring ends (29, 30) of the ring being seated on the upper part of the oil feed pipe.