1）Hard rock teeth apply to : high compressive strength, hard, thick hard mezzanine, such as hard shale, limestone, sandstone, dolomite and so on.
2)Medium hard rock teeth apply to : low compressive strength of the soft to medium strata, medium soft shale, medium soft limestone, medium soft sandstone and medium hard interlayer lamination.
3)Hard rock teeth apply to : low compressive strength of soft formations, such as mudstone, gypsum, salt rock, soft shale, soft limestone.
 

According roller bit bearing structure divided into metal and rubber seals bearing, tooth IADC code 437-637 tricone bit palm can assemble various types and diameter of combination drill bit for a variety of drilling rock formations.