Abstract: A piston head for a die-casting machine, in particular a cold chamber type, comprises a front surface for pushing the molten metal and a side wall extending around a head axis, wherein at least one ring seat is provided in said side wall suitable to receive a sealing ring. The bottom of the ring seat is connected to the front surface through holes or connection channels for a metal flow under the sealing ring. The holes or connection channels lead into an annular peripheral portion of said front surface, said annular peripheral portion being inclined with respect to a front plane orthogonal to said head axis so as to be turned towards said head axis.

Abstract: A piston for cold chamber die-casting machines includes a piston body terminating at the front with a frontal surface pushing molten metal and at least one ring seat made around the body suitable to house a respective sealing ring. An annular distribution channel is made in an intermediate annular portion of the bottom surface of the ring seat, which communicates with the frontal surface of the piston through at least two communication holes made in the piston body for flow of molten metal into the distribution channel, under the ring. The communication holes are inclined in relation to the piston axis and have a through section which increases towards the distribution channel.

Abstract: A piston for cold chamber die-casting machines includes a piston body terminating at the front with a frontal surface pushing molten metal and at least one ring seat made around the body suitable to house a respective sealing ring. An annular distribution channel is made in an intermediate annular portion of the bottom surface of the ring seat, which communicates with the frontal surface of the piston through at least two communication holes made in the piston body for flow of molten metal into the distribution channel, under the ring. The communication holes are inclined in relation to the piston axis and have a through section which increases towards the distribution channel.