Insert Designation Chart Shape (e.g. " C NMG432" / " C CMT32.51") Clearance or Relief Angle (e.g. "C N MG432" / "C C MT32.51") - 5 - Code Letter Description Diagram Nose Angle A 85° parallelogram 85° B 82° parallelogram 82° C 80° diamond 80° D 55° diamond 55° E 75° diamond 75° H hexagon 120° K 55° parallelogram 55° L rectangle 90° M 86° diamond 86° N 55° parallelogram 55° O octagon 135° P pentagon 108° R round full radius S square 90° T triangle 60° V 35° diamond 35° W trigon 80° X sp. parallelogram 85° Code Letter Angle Diagram N 0° A 3° B 5° C 7° P 11° D 15° E 20° F 25° G 30°