Drill body of an indexable insert drill and indexable insert drill comprising such a drill body

A drill body of an indexable insert drill, the drill body being elongated and comprising:

• a rear end and an opposite front end, wherein a central longitudinal axis of the drill body extends between the rear end and the front end of the drill body;
• a shank portion located at the rear end of the drill body and configured for attachment to a machine tool;
• a head portion located at the front end of the drill body;
• at least a first chip flute and a second chip flute extending alongside of each other along a part of the drill body from the head portion towards the shank portion, the first and second chip flutes being separated from each other in the circumferential direction of the drill body by intermediate ribs formed in the drill body and extending alongside of the chip flutes, wherein each first and second chip flute and each rib extend in a helically curved path along the associated part of the drill body;
• a first insert seat configured to receive a first cutting insert and located at a transition between the first chip flute and a front face of the drill body;
• a second insert seat configured to receive a second cutting insert and located at a transition between the second chip flute and the front face of the drill body;
• and
• coolant ducts arranged in and extending along a respective one of said ribs, wherein each coolant duct extends in a helically curved path along at least a part of the associated rib, and wherein each coolant duct has an upstream end with an inlet opening facing the rear end of the drill body and a downstream end with an outlet opening in the head portion, wherein each coolant duct has a cross-sectional area that varies in the axial direction of the coolant duct such that it has a smaller cross-sectional area at its outlet opening than at its inlet opening.