A cutting head of a reamer has a cutting head forward end, a cutting head rear end distal the cutting head forward end, and a peripheral surface therebetween. The peripheral surface has at least two wiping pads that extend rearwardly from the cutting head forward end. At least one cutting section extends between two consecutive wiping pads and has a chip evacuation flute that extends rearwardly from the cutting head forward end and a cutting edge that is formed at the intersection of a rake surface and a relief surface. A chip former extends rearwardly from the rake surface. The chip former has a front portion that is slanted rearwardly and downwardly from the rake surface, and, a rear portion that is slanted rearwardly and upwardly with respect to the rake surface. A rear end of the rear portion joins the chip evacuation flute and form therewith a forming internal angle.