Mechanically-adjustable pitch propeller

A mechanically-adjustable pitch marine vessel propeller (2) attached to a shaft (1) driven by an engine of a marine vessel, comprising a substantially cylindrical hollow (3.1) hub (3) and a plurality of blades (10) extending radially outwardly from said hub (3) and being capable of partially rotating around an axis being in a radial direction relative to the hub (3), characterized in that the propeller comprises an actuator (4) movable linearly along the axis of the hub (3) and at least one motion transmission means (10.2) communicating with the actuator (4) and each blade (10) for converting the linear motion of the actuator (4) into the rotational motion of each blade (10) in a radial direction relative to the axis of the hub further comprising a threaded shaft (5) providing the linear motion of the actuator along the axis of the hub, the threaded shaft (5) communicating with the actuator and wherein the shaft (5) is supported in a hole (4.7) formed at the center of an actuator disc (4.6) for rotating the shaft relative to the actuator disc (4.6), further comprising a conical piece (9) provided to an end (3.5) of the hub and having a gradually tapering form, the conical piece (9) comprising a circular shaft cavity (9.3) extending axially starting from the tapered end thereof, and the conical piece (9) comprising screw threads (9.2) formed along a certain length on the shaft cavity (9.3) and being compatible with the threads of the threaded shaft (5).