TurningMillingDrillingTechnicalInformationIndex Chip breaker overview General turning Negative inserts PCBN & PCD inserts A Flat H K Solid CBN insert for machining od steel and cast iron. Ceramic inserts B Flat K H Ceramic inserts for machining of low hardened steel and cast iron. Positive inserts C Fine-finishing USF P M Single sided chip breaker for fine finishing. Sharp cutting edge with large hollow flute, excellently suitable for machining small work pieces. G-tolerance for high repeatability. D R/L P M Single sided chip breaker for fine finishing. Excellent for high surface quality. G-tolerance for high repeatability. SF P M E Single sided chip breaker in combination with cermet grades. Geometry with high sharpness for improved chip control and great surface quality. Ideal for machining with small cutting depths and feed rates. A 21