12 1/4 in MDSiR813(311.15 mm)

Product ID: 66191A0001 ER 26460

Design Specifications

Total Cutters128
Rolling Cutter Count26
Cutter Size13mm (1/2 in)
Face Cutters(58) 13mm
Gauge Cutters(8) 13mm
Cone Cutters(14) 13mm
Back-Up Cutters(48) 13mm
Blade Count8
Nozzles8 Standard Series 60N
Bit Connection6 5/8 Reg
Junk Slot Area, in224.225
GaugeLength: 3" Protection: Options Available
LengthMake-Up: 11.4 Overall: 16.338
Fishing NeckDiameter: 8 Length: 3.521

Operating Parameters

Bit SpeedRotary Steerable BHA & Downhole Motors
Weight-on-Bit20,000 To 60,000 (lbs)
9,090 To 27,270 (daN)
9 To 27 (Tonnes)
Flow Rate galUs/min500 To 1000
Hydraulic Horsepower, HSI1 To 6
Recommended Make-up Torque47,300 To 47,800 pound ft
The operating parameters listed here are general parameters, please contact your local Smith Bits representative for precise recommendations for your individual well.



The ONYX 360 rolling cutter feature allows the PDC element to rotate enabling the full circumference of the diamond edge to be utilized. This prevents a wear flat developing in only one place thereby maintaining cutter sharpness for improved drillbit durability.

The PX feature places thermally stable diamond inserts (TSP) on the gauge to maximize gauge retention and extend bit life.

Low Exposure (MDOC – Managed Depth Of Cut) Cutter backing raised to minimize excessive depth of cut because of formation heterogeneity to reduce cutter loading and minimize torque in transitional drilling. Minimizes cutter breakage and extends bit life.