... 3.long working experience commodity:12 1/4 tricone bit 1.material:carbide 2.various types for different formations3.cutting ... (5 1/8”),133.3mm(5 1/4”),139.7mm(5 1/2”),142.8mm(5 5/8”),149.2mm ... /8”),215.9mm(8 1/2”),222.2mm8 3/4”) 241.3(9 1/2”),244.4(9 5/8”),250.8( ... .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”), ...