1\ Journal bearing. Hardfaced head bearing surface.Cone bearing inlaid with friction reducing alloy and thensilver-plated. The load capacity and seizure resistance of the bearingis greatly improved. 2\ High wear resistance and excellent cuttingability of the insert bit are given full play by using carbide compactsof high strength and high toughness in combination with optimizedcompact numbers and rows, the exposure height and special shapedcompacts. For steel tooth bit, the tooth surface is hardfaced with newtype of wear resistant material and thus extended working life of thecutting structure while maintaining high ROP. 3\HJ series bit uses themost advanced sealing technology in the world, i.e. the metal face seal(MFS). It can perform consistently in high speed drilling applications,and is the ideal tool for drilling directional and horizontal wells. Incomparison with conventional rubber O-ring sealed bits, the averageworking life (total drilling hours) of HJ series bit under the conditionof the same operating parameters can be increased by 35%.