The above parameters are only for reference. Optimized parameters are determined by drilling process and lithology of formations on site.

Design character：

●Very soft： 

such as soft marl, clay, salt, etc.

●Hardfacing on shirttail 

This feature can provide better protection for seal and bearing to extend the bit’s service life. 

●Cutting structure： 

Hardfaced gage and tooth surfaces. 

●O-ring sealed journal bearing： 

Journal bearing structure with head bearing hardfaced and cone bearing silver plated to improve load  capacity and anti-galling ability of the bearing. More wear and high-temperature resistant highly saturated Buna-N rubber O-ring is used to improve reliability. Larger O-ring section reduces pressure on the seal, and the boss at outer end of the seal is also helpful for reliability of the  seal.Surface of the thrust bearing couple are specially treated for decreasing friction and increasing  rigidness, load capacity of the bit and anti-galling ability of the bearing are consequently improved.