A threshing and separating system (24) for an agricultural harvester (10) includes a concave (42) having a plurality of perforations； a rotor (40) having an outer surface (82) and at least partially enclosed by the concave (42)； and a plurality of rasp bars (80, 120) connected to the outer surface (82) of the rotor (40), each rasp bar (80, 120) having a working surface (92, 128) defining a respective working angle (Wα) relative to a tangent (T) of the outer surface (82). The threshing and separating system (24) is characterized in that at least one of the rasp bars (80, 120) is an adjustable rasp bar (80, 120) with an adjustable working surface (92, 128) pivotably coupled to the rotor (40) and an actuator (102, 122) coupled to the adjustable rasp bar (80, 120) is configured to selectively pivot the adjustable working surface (92, 128) to adjust the respective working angle (Wα) of the adjustable rasp bar (80, 120).
