... of different fields,mining,hydrology,water well drilling and oil well drilling.The characteristic of the TCI ... ,5. Hours in the rotary cone bit with the impact, crushing and shearing the role of broken rock.6. ... to the soft, medium and hard of various strata.7. Reasonable price and long working life.Size and types availableCommon sizes: 6, ... 8" Kingdream HAS 447G TCI Tricone drill bit with best price