... 7/8”)152.4mm(6”),155.5mm(6 1/8”),158.7mm(6 1/4”),161.9mm(6 3/8”),165.1mm(6 1/2”)190 ... 311.1(12 1/4”),346.0 (13 5/8”),349.2(13 3/4”)374.6(14 3/4”)381(15”),393.7 ... (15 1/2”),406.4(16”)444.5(17 ... 1/2”),508(20”),558(22”),609.6 ... (24”)660.4(26”) Steel tooth(IADC)111, 121,131117,124,126 ...