Foreword
Understanding IADC codes makes choosing the right drill bit much simpler. Whether you’re picking a Tricone or a PDC bit, paying attention to the small details is key. Make smart choices to keep your drilling operations running smoothly and achieve success with precision.
This guide includes diagrams, charts, and real-world examples to help you fully grasp IADC codes and their role in selecting drill bits.
Let’s dive into these codes so you can confidently choose the best bit every time
The Basics of the IADC Coding System
Established in 1940, the IADC (International Association of Drilling Contractors) is an organization dedicated to advancing drilling techniques, improving safety, and supporting drilling contractors worldwide.
IADC codes are a standardized system used to classify and describe the features of Tricone and PDC drill bits. This system provides a clear and consistent way to represent a bit’s design, its suitability for specific rock formations, and any special features.
These codes are widely recognized, making it easier for professionals around the world to communicate effectively, reducing mistakes and confusion.
For more details, check the IADC official website.
How the IADC Code Works
The IADC code is a three-digit system. Here’s what each digit means:
First digit: Indicates the general classification based on rock hardness and formation type.
Second digit: Provides more details about the formation characteristics.
Third digit: Specifies the bit type or any special features.
Fourth digit (Optional): Additional features.
Steel Tooth Tricone Drill Bit (1XX-3XX)
Steel Tooth Tricone Drill Bit, A.K.A. Milled Tooth Drill Bit (short for MT drill bit) is for SOFT terrain formation (if we have to divide all the formations into two types of SOFT and HARD). It typically refers to soil layer, but sometimes it also means some ground layers with very soft rock composition. In fact, it is very hard to difine all the layers with specific numbers or classifiable words. So, your own drilling experience or the technical advice from expert would be helpful to your selection of HDD tricone bits.
T.C.I. (Tungsten Carbide Insert) Tricone Drill Bit (4XX-8XX)
Tungsten Carbide Insert Drill Bit (short for T.C.I. drill bit) is for HARD terrain formation (if we have to divide all the formations into two types of SOFT and HARD). It typically refers to rock layers. There are two mostly-used codes for rock layers, IADC537 and IADC637. 537 is for medium hard or less abrasive rocks, while 637 is for hard rocks or abrasive rocks.
