1: Journal bearing  .Hardfaced head bearing surface.Inner hole of cone is silver -plated .The load capacity and seizure resistance of the bearing is greatly improved..

2: O ring seal is made of the more wear resistant and high saturated buna -N with the increased seal section and  precisely designed  scaling flange  in the cone sealing area has increased the reliability of the seal.

3:All rubbercompensator 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 .

4:high wear resistance and  excellent cutting  ability of  the insert bit are given  full play by using carbide compacts of  high strength and high thoughness in combination with optimized  compact numbers androws ,the exposure height and special shaped compacts .For steel tooth bit ,the tooth surface is hard faced with new type of  wear resistant material and thus has extended working life of the cutting structure while still  maintaining high ROP.