| 摘要 |
A drill bit for connection on a drill string has a hollow tubular body with an end cutting face and an exterior peripheral stabilizer surface with cylindrical sintered carbide inserts positioned therein. Nozzle passages extend from the interior of the bit body through the cutting face for receiving a removable and interchangeable nozzle member therein. The nozzle has a fluted or non-circular cross-section with grooved portions or out of round portions providing sufficient clearance for drilling fluid to continue to flow through the nozzle even when the main passage thereof is blocked with mud particles or the like. The cutting face has a plurality of recesses therein which receive, by an interference fit, a plurality of cutting elements of the type known as Stratapax, consisting of a cylindrical stud having an angular supporting surface with a cutting disc bonded thereon consisting of sintered carbide having a cutting surface of polycrystalline diamond. The recesses in the cutting face have milled offset recesses adjacent to the edges thereof which are sized and positioned to permit the cutting discs to be partially recessed and to restrain the cutting elements from rotation during use.
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