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Technical Specifications

 

12 1/4 R7

 Diameter: 311.1mm (12 1/4")  
IADC Code: 311  
Design number: UT643  
State standard designation: Т-ЦГВ  
 

Specification
Gradient angle of axle journal 36°
Axle journal offset relative to drill bit axis 1.60 mm
Bearing type Roller bearing
Sealing None
Total number of inserts (inner/heel row) 193 (118/75)
Total number of insert rows (inner/heel row) 11 (8/3)
Number of changeable nozzles 4
Connecting thread З-152 (6 5/8 REG)
Drill bit net weight, kg 83.00
Drill bit gross weight, kg 85.40
 

Recommended Drilling Conditions
Rotation speed 600-40 rpm
Thrust load 11.00-26.00 t (24200 - 57200 lbs)
The lower level of rotation speed value corresponds the upper level of thrust load value and vice versa.
 

Purpose
The drill bit is designed for drilling hard formations
 

Design Features
Combined circulation (central and side) for what the screw from the central unit must be unscrewed.

The shirttail and leg entering edge are hardfaced with tungsten carbide

Variant of additional reinforcement by carbide inserts of a paw is possible
 

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