FIELD: cutting tools.
SUBSTANCE: cutting insert has opposite top and bottom end surfaces and peripheral surface containing three side surfaces and three angular surfaces. Each angular surface crosses the upper end surface to form an upper cutting edge, and each side surface has a mounting surface. Lower end surface has three radially outwardly facing bottom thrust surfaces. Said three mounting surfaces form a first imaginary triangle having three first bisector planes and three mounting planes, and three lower thrust surfaces form a second imaginary triangle having three second bisector planes. None of the first and second bisector planes is coplanar, and each mounting plane crosses two of the upper cutting edges. For each position of step-by-step movement of cutting insert in seat for receiving insert of cutting tool one of mounting surfaces and one of lower thrust surfaces are in contact with walls of their seat.
EFFECT: higher stability of fastening of cutting insert in seat of housing with compact mounting facility.
23 cl, 17 dwg
