Drilling Tools

Types of Rock Drilling Tools

1. Drill Bits

These are the cutting tools at the end of the drill string.

• Button Bits: Have tungsten carbide buttons; used in hard rock.
• Chisel Bits: Used for softer rock and shallow drilling.
• Cross Bits: Have a cross shape; suitable for medium-hard rock.

2. Drill Rods

• Connect the drilling machine to the bit.
• Transfer rotation and impact energy.
• Can be hollow (for air/flushing fluid) or solid.

3. Shank Adapters

• Connect the drill rod to the rock drill.
• Transfer impact and rotation forces from the machine to the drill string.

4. Coupling Sleeves

• Connect two drill rods together in long hole drilling.

5. DTH (Down-the-Hole) Hammers

• Pneumatic hammers that sit directly behind the drill bit.
• Used for deep hole drilling and hard rock.
• Delivers powerful impact directly at the drill bit.

6. Top Hammer Tools

• Impact force is generated by a hammer outside the borehole (on the drilling machine).
• Used for shorter holes and less hard formations.

🛠️ Applications

• Mining: Blasting holes, exploration, production drilling.
• Construction: Foundation drilling, anchoring, tunneling.
• Oil & Gas: Exploration drilling (although typically more advanced rotary tools are used).
• Geothermal & Water Wells: Deep hole drilling into bedrock.

🧱 Materials Used

• Tungsten Carbide: Extremely hard; used in cutting tips.
• High-Strength Steel: For rods and shanks; resists wear and impact.
• Alloy Steel: Heat-treated for toughness and fatigue resistance.

⚙️ Drilling Methods

• Percussion Drilling: Repeated hammering action breaks rock.
• Rotary Drilling: Bit rotates to grind away rock.
• Rotary-Percussion (Combined): Common in hard rock drilling.

✅ Factors to Consider When Choosing Rock Drilling Tools

• Rock hardness and abrasiveness.
• Hole depth and diameter.
• Drilling method (top hammer vs DTH).
• Cost-effectiveness and wear resistance.
• Bit shape and button configuration.