A METAL CUTTING INDEXABLE DRILL TOOL

A metal cutting indexable drill tool (100), comprising: an elongated drill body (101) having a boring shaft (102) and a mount shank (103); a center drill insert (104) mounted at a distal end (105) of the boring shaft (102) in an insert seat (106) configured to hold the insert against a bottom of the insert seat (106); a drill flute (107) of the boring shaft (102) configured to direct and form a chip from the center drill insert (104), wherein the drill flute (107) comprises a chip forming surface (108) at a distal end (109) of the drill flute (107); characterized in that the chip forming surface (108) is perpendicular to the bottom of the insert seat (106) for the center drill insert (104); and in that the chip forming surface (108) is arranged at a distance X from a peripheral corner (110) of the center drill insert (104) to a point (301) on a curve (302), which curve is formed by the intersection of the chip forming surface (108) and an imaginary inscribed sphere (302), wherein the center (303) of the imaginary inscribed sphere coincide with the center of the distal end (105) of the boring shaft (102), wherein the radius of the imaginary inscribed sphere is defined by the peripheral corner (110) of the insert (104); and wherein the distance X divided with the diameter of the drill tool Dc is equal to a chip parameter A which is indicative of the chip diameter to boring diameter ratio; wherein the chip parameter A is 0.3 ≤ A ≤ 0.5.