13 1/2" FSA517G Carbide Insert Drill Bits With 3 7/8 inch - 18 1/2 inch Size

13 1/2" FSA517G , Rubber Sealed Journal Bearing , Sealed Friction Bearing , TCI Tricone Bit

SIZE AVAILABLE

Form 3 7/8inch to 18 1/2inch

RECOMMENDED DRILLING PARAMETERS FOR APPLICATION

The above chart represents commonly available sizes and types, we do produce other sizes and types of rock bits which do not appear on this list. Please contact us for more information.

Journal bearing

- The bearing load carrying surface
- Journal angle is the angle formed by a line perpendicular to the axis of the journal and the axis of the bit
- Magnitude affect the size of the cone
- Increase in angle decrease cone size
- The smaller the angle the greater the gouging and scraping action
- Optimum journal angle for soft and hard rock bits are 33 and 36

ROLLER CONE BIT FLUID CIRCULATION

Drilling fluid passes from the drillstring and out through nozzles in the bit. As it passes across the face of the bit it carries the drilled cutting from the cones and into the annulus. The original design for rock bits only allowed the drilling mud to be ejected from the middle of the bit . This was not very efficient and led to a build up of cuttings on the face of the bit (bit balling) and cone erosion. A more efficient method of cleaning the face of the bit was therefore introduced. The fluid is now generally ejected through three jet nozzles around the outside of the bit body . The turbulence created by the jet streams is enough to clean the cutters and allow efficient drilling to continue.