Rotary cutting tool and indexable insert

A rotary cutting tool orientable type (1) having at least one indexable insert (3), said part being inserted (3) designed with substantially rectangular shape having a pin hole, being linear each of the two sides located at symmetrical positions of the four sides constituting said indexable insert (3), serving one of them as an edge of outer peripheral cutting (9), including each of the other two sides located at symmetrical positions a portion configured as an arc or shaped substantially as an arc or shaped like a rounded straight line at both its ends, one of them being as a main cutting edge (7), and a linear portion that continues from the main cutting edge (7) and it serves as an edge of the inner peripheral cutting (8), wherein the outer edge peripheral cutting is wedged rearwardly relative to the central axis of the tool and said main cutting edge (7) is designed to be between 3 and 35 degrees angle (k) cutting edge and has a length over which said main cutting edge (7) comes into contact with a workpiece, being substantially invariable length even when carving work is repeated.