TurningMillingDrillingTechnicalInformationIndex General turning Chip breaker overview Negative inserts A Roughing HDR P M Single sided chip breaker with high cutting edge stability and deformation resistance. Excellent for roughing with high cutting depths in steel and stainless steel. B HPR P K Single sided chip breaker with high cutting edge stability and large chip space. Excellent for heavy roughing in steel and cast iron. Flat K C Double sided insert without chip breaker. Stable cutting edge design, due to missing microgeometry. Excellent for roughing in cast iron. SNR S M D Double sided chip breaker for roughing. Wide range of application due to excellent balance of sharpness and cutting edge stability. PCBN & PCD inserts Flat N H E With brazed CBN or PCD cutting edge. For machining of hardened steel (CBN) or non-ferrous metals (PCD). A 20