Abstract: The invention relates to a rotary drill bit for drilling a borehole in an earth formation, the drill bit comprising a first and a second disc cutter, each disc cutter being arranged to roll along the borehole bottom during rotation of the drill bit and thereby to cut respective first and second substantially circular, radially spaced cuts in the borehole bottom so that a body of rock material is defined between said cuts. The second disc cutter is arranged to cut into the bottom of the borehole at a selected rotational interval of the drill bit behind the first disc cutter and to shear-off said body of rock material in the direction of the first cut. Each disc cutter includes a set of mutually spaced cutting members arranged to create, during a turn of the drill bit, a corresponding set of cut sections of the cut created by the disc cutter, and wherein the cutting members are arranged so that the sets of cut sections created during subsequent drill bit turns are staggered relative to each other.