Abstract: This cutting insert, designed to be inserted into the cutting head of a drill or other similar rotary boring tool, has an arced overall shape, with a concave flank and a convex flank. These flanks are connected by a base face, by two straight end edges one of which is able to act as a guide for the drill and, at the opposite end to the base face, by at least one cutting part, with at least one cutting edge and/or at least one tip. Also described is a boring tool, the cutting head of which comprises such arced inserts, arranged laterally, and associated with a central insert.