This is Shoulder and Face Milling Cutter used mainly in CNC Milling and Manual Milling Machine with ISO Carbide Insert , Using this can reduce the cost really low compared to HSS and changing of insert time is also very low , They are hardened 45-50 HRC to not wear out , Pockets are well designed so insert and pocket seat have no gap in them , Run out tolerance is maintained by grinding by center to center and they have center hole both sides , you can use any ISO inserts of APMT1135 into this ,