The present disclosure relates to a quadrangular indexable drill insert. The drill insert includes a substantially flat top surface, a bottom surface and a side surface adjoining the top and bottom surfaces. The side surface comprises four identical cutting edges intersecting the top surface; each cutting edge comprises a first part edge oriented inwardly towards axis of the drill body. A second part edge tangential to an imaginary inscribed circle diameter connected to the first part edge through a convex curve. A third part connected to the second part edge through concave curve and a fourth part edge connected to the third part edge though a convex curve. The insert further includes a curved nose portion at four corners, each adjoining a first part edge of one cutting edge with a fourth part edge of a succeeding cutting edge.