Oil-control ring for an internal combustion engine

An oil-control ring for an internal combustion engine, to be mounted between sidewalls of a respective groove of a piston reciprocating within a cylinder of an internal combustion engine, said ring comprising:

• two ring segments;
• an annular expander disposed between the two ring segments, in order to force the ring segments radially against the cylinder and axially against adjacent sidewalls of the groove, said expander having a support body with two ends, said support body defining a seating plane for each of said ring segments;
• at least one expander portion axially projecting from the support body of the expander beyond at least one of the seating planes of one of the two ring segments, said expander portion projecting from one of the two ends of the expander;
• and
• at least one superficial irregularity which is defined by an axial recess provided in a thickness of said at least one ring segment and opened to the expander, to receive and engage a respective expander portion and which is dimensioned to be contained in the thickness of said at least one ring segment, in order to rotatively lock said at least one ring segment relative to the expander.