2015 hot sale API milled steel tooth Drill Bits

There are rich and diverse roller bits to meet different requirements of formations and rotary speeds. The sizes of the gage diameter and the types of bit are strictly designed in accordance with the standards API Spec.7. There are not only rubber sealed bearing bits but also metal face sealed bearing bits, and all bits are lubricated by new type of wear resistant grease that can sustain high temperature up to 250??蹎制??. The surfaces of main or key parts are hardfaced and treated with friction reducing technology. They can enhance gage protection and prolong the life of bit. Center nozzle is equipped for bits of larger sizes.