1、 Journal bearing. Hardfaced head bearing surface. Cone bearing inlaid with friction reducing alloy and then silver-plated. The load capacity and seizure resistance of the bearing is greatly improved. 2、 High wear resistance and excellent cutting ability of the insert bit are given full play by using carbide compacts of high strength and high toughness in combination with optimized compact numbers and rows, the exposure height and special shaped compacts. For steel tooth bit, the tooth surface is hardfaced with new type of wear resistant material and thus extended working life of the cutting structure while maintaining high ROP. 3、HJ series bit uses the most 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. In comparison with conventional rubber O-ring sealed bits, the average working life (total drilling hours) of HJ series bit under the condition of the same operating parameters can be increased by 35%.

BIT Diameter (In):6 1/2"   
BIT Diameter (mm):165.1
IADC CODE    :437、447
API RGE:3 1/2″
Applicable Formations:
soft formation with low compressive strength and high drillability，such as softshale、clay、salt,soft limestone ,etc
Recommended Drilling Parameters       
WOB (kn/mm)    :0.35~1.00
（bit dia）   
Speed r/mm:280~70   
N.W.(KG)    :17
G.W.(KG)    :18
Size(mm)    :205*205*350