Maxdrill 12 Inch IADC 127/537 Tricone Bit for Water Well Drillin IADC Thread Dia(mm) weight(kg) Air Pressure Rotary Speed 542 3 1/2"API 171 21 0.2-0.4MPa 110-80RPM 632 3 1/2"API 171 20 0.2-0.4MPa 120-50RPM 642 3 1/2"API 171 20 0.2-0.4MPa 120-50RPM 732 3 1/2"API 171 21 0.2-0.4MPa 90-60RPM 412 4 1/2"API 200 34 0.2-0.4MPa 120-90RPM 545 4 1/2"API 200 34 0.2-0.4MPa 110-80RPM 635 4 1/2"API 200 34 0.2-0.4MPa 100-60RPM 545 4 1/2"API 216 36 0.2-0.4MPa 110-80RPM 412 4 1/2"API 229 50 0.2-0.4MPa 120-90RPM 845 4 1/2"API 229 50 0.2-0.4MPa 80-50RPM 545 6 5/8"API 251 65 0.2-0.4MPa 110-80RPM 642 6 5/8"API 251 65 0.2-0.4MPa 100-60RPM 645 6 5/8"API 251 65 0.2-0.4MPa 100-60RPM 712 6 5/8"API 251 65 0.2-0.4MPa 90-60RPM 715 6 5/8"API 251 65 0.2-0.4MPa 90-60RPM 745 6 5/8"API 251 65 0.2-0.4MPa 90-60RPM 632 6 5/8"API 270 83 0.2-0.4MPa 100-60RPM 742 6 5/8"API 279 74 0.2-0.4MPa 90-60RPM 545 6 5/8"API 310 100 0.2-0.4MPa 110-80RPM 642 6 5/8"API 311 100 0.2-0.4MPa 110-60RPM 645 6 5/8"API 311 100 0.2-0.4MPa 110-60RPM 732 6 5/8"API 310 100 0.2-0.4MPa 90-50RPM