Tungsten Carbide Tooth Steel Tooth Series KUST Bit Selection 2 Formation type 3 Bearing/Gauge 4 (unrequired) Additional features 1 2 3 4 5 6 7 1 A Air application (journal bearing with air nozzles) 2 Soft B Special bearing seal 4 1 C Center jet 2 2 Medium 3 4 1 2 3 Hard 3 4 1 2 Soft 3 4 1 5 Soft to medium 2 3 4 1 2 6 Medium 3 4 1 Standard open roller bearing Standard open roller bearing, air-cooled Standard open roller bearing with gauge protection Sealed roller bearing Sealed roller bearing with gauge protection Sealed friction bearing Sealed friction bearing with gauge protection D Deviation control HG Н J L Lug pads M Motor application S Standard steel tooth model T Two cone W Enhanced cutting structure E Extended jets (full length) Extra gauge/body protection Horizontal/steering application Jet deflection 2 7 Hard 3 Predominantly chisel tooth inserts 4 1 2 8 Very hard 3 Y Predominantly conical inserts Z Other shape inserts 4 KUST Bit Selection 2 Bit body Formation type Very soft Soft Soft to medium The below table is used for PDC bits classification: Medium no code 5 S-steel Medium hard 6 M-matrix Hard 7 D-diamond Extremely hard Natural diamond 234 19 Size of PDC cutters Bit profile 1 2 3 4 1 2 3 4 1 Diamond cutters type Thermally stable (TSP) Combination Impregnated diamond ει 8 Short fishtail Short profile Medium profile Long profile 4