| 摘要 |
A drill bit for boring a bore hole in an earthen formation comprises a bit body having a pin end, a cutting end and a longitudinal axis and including at least two legs extending from the cutting end, each of the legs including a leading side surface, a trailing side surface, and a shoulder, each of the legs further including a bearing and a cutter cone rotatably supporte d on the bearing, and the bit body further including a fluid flow system, including a flowway in said pin end, the flowway being in fluid communication with at least one exit port in the cutting end, the bit body further including a neck between the shoulders and the pin end and a hard, wear- resistant material on at least a portion of the neck.
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