Tricone Rock Bits
1, 2, and 3 designate STEEL TOOTH BITS with 1 for soft, 2 for medium and 3 for hard formations.
4, 5, 6, 7 and 8 designate TUNGSTEN CARBIDE INSERT BITS for varying formation hardness with 4 being the softest and 8 the hardest.
1, 2, 3 and 4 are further breakdown of formation with 1 being the softest and 4 the hardest.
This digit will classify the bit according to bearing/seal type and special guage wear protection as follows:
- Standard open bearing roller bit
- Standard open bearing roller bit, air-cooled
- Standard open bearing roller bit with gauge protection which is defined as carbide inserts in the heel of the cone
- Sealed roller bearing bit
- Sealed roller bearing bit with gauge protection
- Journal sealed bearing bit
- Journal sealed bearing bit with gauge protection
The following letter codes are used in the fourth digit position to indicate additional features:
A. Air Application
R. Reinforced Welds
C. Center Jet
S. Standard Steel Tooth
D. Deviation Control
X. Chisel Insert
E. Extended Jet
Y. Conical Insert
G. Extra Gage Protection
Z. Other Insert Shape
J. Jet Deflection
There are primarily four (4) types of bearing designs used in tricone drilling bits:
1.) STANDARD OPEN BEARING ROLLER BIT: On these bits the cones will spin freely. This type of bit has a front row of ball bearings and a back row of roller bearings.
2.) STANDARD OPEN BEARING ROLLER BIT FOR AIR DRILLING: Cones are similar to #1, but have air injection directly to the cones to cool the bearings. Air flows into the cone through the passage ways inside the pin. (Not for mud applications)
3.) SEALED BEARING ROLLERS BITS These bits have an O-Ring seal with a grease reservoir for bearing cooling. The seals acts as a barrier against mud and cuttings to protect the bearings
4.) JOURNAL BEARING ROLLER BITS These bits are strictly oil/grease cooled with nose bearings, O-Ring seal and a race for maximum performance.
Based on the IADC Bit Classification System located in the IADC Drilling Manual, 11th Ed. – Redesigned, 2007