DTH Drill Bit

DTH (Down-The-Hole) drill bit is a critical component in DTH drilling systems, used primarily in mining, construction, water well drilling, and geothermal drilling. It is designed to work with a DTH hammer, which delivers rapid, high-impact blows directly to the bit while compressed air or fluid flushes out the cuttings.

Key Features of DTH Drill Bits:

Material & Construction:

- Made from high-strength alloy steel (e.g., 24CrMo, 30CrNiMo).

- Hardened surfaces or tungsten carbide inserts for wear resistance.

Types of DTH Bits

- High air pressure DTH drill bit

- Medium-Low air pressure DTH drill bit

Design & Function

Hole for Air/Flushing: Compressed air exits through the bit, removing cuttings.

Gauge Protection: Carbide inserts on the sides prevent bit wear.

Threaded Shank: Connects to the DTH hammer.

Applications

Blast hole drilling (mining).

Water well drilling.

Geothermal drilling.

Construction piling.

Advantages of DTH Bits:

✔ High penetration rates in hard rock.

✔ Better hole straightness compared to rotary drilling.

✔ Efficient cuttings removal due to air flushing.

Common Sizes:

Diameter Range: Typically 3.5 to 16 inches (90mm to 400mm).

Common Thread Types: API Regular, API Modified, RETRAC, COP, etc.

Pulanka offers DTH bits having concave, flat face and convex bit face configuration：

Concave Face Hammer Bits

● Capable of drilling straighter holes in medium to hard rock which is broken or less consolidated

● Offers high penetration rate in the above stated rock conditions

● Has excellent air flushing characteristics

● Predominant face style for majority of drilling conditions

Flat Face Hammer Bits

Features of Flat Face

● Have a superior performance in hard, abrasive and broken rock conditions

● They however have a slower penetration rate in comparison to a concave face bit

Convex Face Hammer Bits

Features of Convex Face bits

● This face has been designed to offer high penetration rate in soft rock such as shale, limestone etc

● They are recognized for having excellent capability for drilling into moderately consolidated rock conditions