GJ/GJT rock bits METAL SEALED rock BIT WITH ROLLER BEATING
GJ/GJT series rock bit adopts metal seal with roller bearing ,which can drill stably with middle to low WOB and middle to high RPM,it is the ideal choice for higher part of well section. The size range of GJ/GJT series rock bit is from8 1/2 to 17 1/2 inch, and IADC varies from 115 to 545.For example:17 1/2 GJT515GC rock bit MAIN STRUCTURE FEATURES sizes of bearing journal and rollers are made larger by arranging the rollers in recesses in cone body. All rubber compensator is used which can limit pressure differential and prevent drilling fluid from entering the lubrication system and this provides the bearing system with good assurance of lubrication. Shirttail and head OD are hardfaced for enhanced gage protection. Center nozzle is equipped for bits of larger sizes. For GJT rock bit,a row of inserts is added between gage row and heel row to trim borehole wall and protect cone shell.