IADC code is short for “International Association of Drilling Contractors”.

The IADC Code for Tricone Bits defines its bearing design and other design features ( SHIRT TAIL, LEG, SECTION, CUTTER).

IADC Codes make it easier for drillers to describe what kind of rock bit they are looking for to the supplier.

The most common IADC code used in HDD is such as 127, 517, 637 etc. Let us check what does it stands for.

FIRST DIGIT

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.

SECOND DIGIT

1, 2, 3, and 4 help further breakdown the formation with 1 being the softest and 4 the hardest.

THIRD DIGIT

This digit will classify the bit according to bearing/seal type – see information on different bearing types – 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

FORTH DIGIT

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