1>API Spec7-1 &ISO 9001:2008 2>Good quality and after-sale service 3>30 years experience in tricone rock bit Size5 5/8”(142.8mm)IADC537Bearing TypeElastomer sealed journal bearingThread Connection3 1/2 API reg pinWOB(KN/mm)0.45~1.0RPM(r/min)120~50Applicable FormationsMedium to hard formations with low compressive strength, such as medium, soft shale, medium soft limestone, medium soft sandstone, ...