... 1) Material: 15CrNi4MO2) Rubber/metal sealed bearing3) Jeurnal/rock bearing 4) Cutting element:hard alloy cutting tooth5) Apply to soft-medium ... (13 5/8”),349.2(13 3/4”)374.6(14 3/4”)381(15”),393.7(15 1/2”),406 ... 1/2”),508(20”),558(22”),609.6(24”)660.4(26”) Steel tooth(IADC)111, 121,131117,124,126,127, ... like 537G3)plz tell the drilling information of the layer.4)plz tell the quantity. 8 1/2 215.9mm iadc ...