IADC Classification Standards for Tricone bit and PDC bit

The IADC classification system, developed by the International Association of Drilling Contractors has been the representative voice of drillers worldwide since 1940. This system of roller cone identification was established in 1987 and expanded in 1992 to include more features.

The first digit represents the hardness of rock formation the drilling tool like Tricone bit or PDC bit are suited for.
Every Tricone bit/PDC bit is designed for a certain type of rock formation, ranked according to hardness.
The tool is assigned a number between 1 and 8 indicating the type of rock the teeth or buttons of a drilling tool are designed for:

1, 2 and 3: Indicate a steel tooth. 1 is engineered for soft rock formations, 2 for medium formations, and 3 for hard formations.

4, 5, 6, 7, and 8: Indicates a tungsten carbide insert (TCI).
Within this category 4 is designated for the softer formations, with 8 representing the hardest formations

The second digit represents further rock formation information
Regardless of tooth type, the second digit takes into account all factors of the bit and ranks the rock formations the drilling tool like Tricone bit or PDC bit is best suited for on a scale from 1 to 4. 1 represents soft formations going up to 4 representing the hardest formations.

The third digit represents the bearing type of the drilling tool like Tricone bit or PDC bit.
For Example, Tricone bit use different bearings depending on the type of material to be drilled.

1, 2 and 3: are for roller bearings. 1 is for standard roller bearings, 2 is for air cooled bearings, and 3 is for open bearing with gauge protection.

4 and 5: sealed roller bearings. 4 is for standard sealed roller bearings, and 5 is for a sealed roller bearing with gauge protection.

6 and 7: sealed journal bearings. 6 is for a standard sealed journal bearing, and 7 is for a sealed journal bearing with gauge protection.

The fourth digit is a letter indicating the special properties of the drilling tool like PDC bit or Tricone bit.
In addition to the buttons, intended rock formations, and bearings used, tricone bit can have numerous other special properties:

A – Air Application

B – Special Bearing

C – Center Jetted

D – Deviation Control

E – Extended Jets

G – Extra Gauge or Body protection

H – Horizontal/Steering

J – Jet Deflection

L – Lug Pads

M – Motor Application

S – Standard Steel Tooth

T – Two Cone

W – Enhanced Cutting Structure

X – Chisel Inserts