... Diameter/InchIADC CODE3 1/2 211, 121, 241, 537….3 7/8 131, 211, 537, 517….4 1/2 211, 121, 241 ... , 537….4 3/4 131, 211, 537, 517….5 1/2 131, 211, 537, 517….6 211, 121, 241, 537….……….. ………………………………12 1 ... , 121, 241, 537….17 1/2 131, 211, 537, 517….18 1/2 211, 121, 241, 537….………..………………………………26 131, 211, 537, 517…. 311 tricone ...