Rock Drill Bits 12 Mill Tooth Bit API Connectiong 6-5/8inch for
Rock Drilling Industry
1 . Descriptions:
Steel Tooth (or Mill Tooth) bits come in many shapes and sizes with
multiple features, and cutting structures to combat downhole
diversities in the different formations you may encounter.
Mill teeth (Steel teeth) tricone are used in the soft rock
formation . Wide gaps between the protruding teeth prevent them
from becoming blocked with material as they cut through the top
layer of material.
2. Specification:
| BIT SPECIFICATIONS |
| Diameter: | 12 ”(304.8mm) |
| Body Type : | Steel Body |
| Tooth Type: | Milled Tooth |
| Bearing : | Sealed Rearing |
| API Thread API Connection: | 6-5/8 API REG |
| IACD CODE : | 126 |
| OPERATION PARAMETERS |
| Weight (Kg): | 82KGS |
| RPM Range (rotary): | 80-220 |
| Weight on Bit(kN): | 76-213N |
| Make Up Torque ( KN): | 38-43 KN.m |
3 . Bit profile
4 . Bearing Types
There are primarily three types of bearing designs used in tricone
drilling bits:
• 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.
• 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
• JOURNAL BEARING ROLLER BITS
These bits are strictly oil/grease cooled with nose bearings,
O-Ring seal and a race for maximum performance.
5. Question :
What we should be pay attention on choosing the tricone drill bit ?
- IADC code passport
- TCI & Steel tooth options
- Additional tungsten carbide inserts on heel rows
- Tungsten carbide coating on cone bodies
- Diamond coated tungsten carbide inserts on the gauge of the cones
- Tungsten carbide inserts on the shirttail of the legs
- Additional central nozzle for cleaning cones
The tricone feature is that they come with their own passport as
below :
- The specification of the cones
- The quality stamp signed by the person who made and checked the bit
- The recommended drilling parameters to get the best performance out
of the bit:
- Bit weight
- Rotation speed
- Flushing volume
Which type of tricone you should choose ?
It depends on the geology you are drilling in and the diameters of
the borehole you are drilling. The International Association of
Drilling Contractors (IADC) have developed an easy use step system
to choose the right tricone for your geology with additional
features such as bit protection for longer production life.
