Disclosed is a piston (1) for a combustion engine, comprising an annular grooved reinforcement (4) that is screwed onto an externally threaded (13) collar (12) located in the piston head area via an internal thread (19) which is mounted on the inside of the grooved reinforcement (4). The grooved reinforcement (4) blocks a recess (14) so as to form an annular, closed cooling duct (21). In order to provide the screwed connection between the collar (12) and the grooved reinforcement (4) with sufficient stability, a radially outward area of the collar (12) is equipped with a bend that points towards the hub. Furthermore, the collar (12) is embodied in an elastically resilient manner so as to bend in the direction of the piston head when the grooved reinforcement is screwed in, thus prestressing the screwed connection.