... medium-hard drilling information 6) Bit size:8 1/2"IADC code:5372,products details 3,Packingor steel box4, ... ”),133.3mm(5 1/4”),139.7mm(5 1/2”),142.8mm(5 5/8”),149.2mm(5 7 ... (6 3/8”),165.1mm(6 1/2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm ... in you inquiry1)the size of the tricone bit.2)the IADC tooth model,like 537G3)plz tell the ... the layer.4)plz tell the quantity. 8 1/2 215.9mm iadc 517 rotary drilling rig