What the Digits in the IADC Codes Mean

purple tricone drill bit If you’ve ever ordered a tricone bit before, you had to use a 4-digit IADC (International Association of Drilling Contractors) code to ensure that you purchased the correct drill bit. You may not have given the code much thought, but those four characters actually communicate a lot of information. This coding system was created to simplify the ordering process for tricone bits and cut down on confusion and incorrect orders being placed. Find out below what each digit stands for.

The Hardness of Rock Formations

The first digit is a number between 1 and 8 that indicates the type of rock the tricone is best suited for.

Numbers 1-3 indicate steel teeth:

  • 1: Suited for soft rock formations
  • 2: Suited for medium rock formations
  • 3: Suited for hard rock formations

Numbers 4-8 indicate a tungsten carbide insert. From 4-8, these bits scale from softer formations to the hardest formations.

Further Rock Formation Information

The second digit includes more rock formation factors. On a scale from 1-4, the bits range from begin ideal for soft formations to the hardest.

Bearing Type

The third digit explains which bearing type the drill bit has:

  • 1-3 are for roller bearings:
    • 1: Standard roller bearings
    • 2: Air-cooled bearings
    • 3: Open bearings with gauge protection
  • 4-5 are for sealed roller bearings:
    • 4: Standard sealed roller bearings
    • 5: Sealed roller bearings with gauge protection
  • 6-7 are for sealed journal bearings:
    • 6: Standard sealed journal bearing
    • 7: Sealed journal bearing with gauge protection

Special Properties

The last digit is a letter that communicates special properties of the tricone bit, such as:

  • B: Special bearing
  • D: Deviation control
  • M: Motor application
  • T: Two cone
  • Z: Other inserts
  • And many others!

Now that you know a little more about the codes and what the digits represent, you can make a more informed decision when you need to purchase new drill bits. Can’t find what you’re looking for in our inventory? Take advantage of our bit sourcing service! We’re happy to use our industry connections and experience to help you find the bit you need for your project.