Guidance of Choosing Tricone Bit

IADC Specification

eg.  537G

First Digit (a)

1,2 and 3 desingate 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 (b)

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

Third Digit (c)

1. Standard open bearing roller bit.

2. Standard open bearing roller bit, air-cooled.

3. Standard open bearing roller bit with gauge protection with is defined as carbide inserts in the heel of the cone.

4. Sealed roller bearing bit

5. Sealed roller bearing bit with gauge protection

6. Sealed joumal bearing bit

7. Sealed joumal bearing bit with gauge protection

Feature Code (d)

The following letter codes are used in fourth digit position to indicate additonal features；

A. Air Application            E. Extended Jet             R. Reinforced Welds               Y. Conical Insert               C. Center Jet

G. Extra Gage Protection                S. Standard Steel Tooth                  Z. Other Insert Shape                D. Deviation Control

J. Jet Deflection                 X. Chisel Insert