1029-SNMX1205AFNN Fast Feed Heavy Duty CNC Milling Inserts Double Sided Octagonal 45 Degree Square Roughing Milling InsertsSNMX Milling inserts for SN12 Cutter Discs [Sharp and wear resistant, one piece is better than three pieces]. Two sided octagonal Sharpness and durability Suitable for high speed cutting at high cutting temperature with smooth chip removal and no sticking.