Selecting the right diamond core bit is one of the most important steps in achieving efficient, cost-effective, and smooth drilling operations. Every geological formation — from soft shale to hard granite — reacts differently during drilling. Using the correct bit type and design not only improves penetration but also extends tool life and ensures better core recovery.
At IndoRock, our diamond core bits are engineered to perform across a wide range of ground conditions found in India and beyond. This guide will help you understand how to choose the right diamond core bit based on your ground type and project requirements.
A diamond core bit cuts rock using industrial-grade diamonds embedded in a sintered matrix. As the bit rotates, the diamonds grind and cut through the rock, producing a continuous cylindrical sample — known as the core.
Each bit is designed with a specific matrix hardness, diamond grade, and crown profile to match a particular rock type. Choosing the wrong bit can cause premature wear, poor penetration, and reduced productivity.
That’s why it’s important to match the bit to your formation hardness.
In diamond drilling, there’s a simple rule:
Soft formation → Hard matrix bit
Hard formation → Soft matrix bit
This means:
1. For soft rocks, the bit must resist rapid wear.
2. For hard rocks, the bit must expose new diamonds quickly to maintain cutting efficiency.
This balance is what ensures steady penetration, long bit life, and clean core samples.
Soft formations are usually less abrasive and easier to drill, but they can wear the bit unevenly if not matched correctly.
1. Hard matrix, low diamond concentration
2. Wider waterways for smooth flushing
👉 Green 1–6 Series – Designed for sedimentary rocks like sandstone, shale, and conglomerate.
1. Prevents over-cutting and rapid wear
2. Maintains hole gauge and stability
3. Delivers consistent core recovery
Use slightly higher rotation speed and moderate feed pressure for best performance.
Medium-hard formations are dense and slightly abrasive, demanding a balanced bit that can cut efficiently without glazing.
1. Medium-hard matrix with moderate diamond concentration
2. Standard crown height (9–13 mm)
👉 Blue 7–12 Series – Ideal for igneous and metamorphic rocks such as basalt, rhyolite, granite, and diorite.
1. 20% faster penetration
2. 30% longer service life
3. Self-sharpening performance for continuous cutting
Maintain steady water flow to prevent overheating and ensure smooth flushing.
Hard formations generate high drilling resistance and extreme wear on bits. The bit must have a softer matrix that continually exposes fresh diamonds as it drills.
1. Soft matrix bit with high diamond concentration
2. Narrow waterways for improved cooling and lubrication
👉 Red 14–16 Series – Engineered for ultra-metamorphic and highly compact formations like banded iron, gneiss, and chert.
1. High cutting rate even in tough rock
2. Extended bit life through even diamond exposure
3. Reduced downtime and cost per metre
Use lower rotation speed with higher feed pressure for better penetration and stability.
Cutter Range Best For: Key Feature: Balanced performance and cost efficiency Designed to suit operational costs and deliver reliable productivity SC All formations are long-life and fast-cutting. Advanced diamond matrix for high performance and durability
Both ranges are manufactured at IndoRock’s Indian facility, using industrial-grade diamonds and a precision sintering process. Each bit undergoes strict quality checks to ensure consistent performance across varying ground conditions.
Choosing the correct bit isn’t just about rock type; it also affects drilling speed, equipment wear, and project cost.
The right bit can:
1. Increase penetration rate by up to 20%
2. Extend service life by 30% or more
3. Lower your cost per metre drilled
4. Reduce reaming and tripping time
5. Improve safety and stability during operation
By matching the correct bit profile to the formation, you achieve higher efficiency and better overall drilling performance.
Every IndoRock bit is engineered for India’s challenging geological diversity, from soft sedimentary basins to hard crystalline formations.
Self-sharpening performance for continuous cutting
Custom matrix and crown designs for your specific formation
High penetration rate with reduced downtime
Proven reliability across field projects nationwide
We also offer custom solutions — from bit profile adjustment to diamond grade selection — to perfectly match your ground condition and drilling goals.
Selecting the right diamond core bit for your geological formation can make the difference between average and exceptional drilling results.
Soft rocks need harder bits, and hard rocks need softer bits — but what really counts is engineering precision and ground-tested performance.
At IndoRock, every bit is designed with this in mind. Whether you’re drilling through shale, granite, or banded iron ore, IndoRock’s range of diamond tools ensures faster penetration, longer bit life, and reliable core recovery, helping you achieve your exploration targets with confidence.
Need help choosing the right bit for your project?
📞 Speak with IndoRock’s technical experts for guidance and bulk pricing.
✉️ Email: info@indorock.co
📍 Location: Pune, Maharashtra, India
IndoRock — Engineered for India’s toughest geology, trusted across the world.
