Products Description
LEANOMS
What Is a 4 Inch DTH Hammer Drill Bit
A 4 Inch DTH (Down-The-Hole) Hammer Drill Bit is a specialized cutting tool used with a pneumatic DTH hammer system to drill holes in rock, soil, or other compact formations.
The DTH hammer drives the bit from directly behind, delivering percussive energy at the borehole bottom.
| Feature | Description |
|---|---|
| Diameter | 4 inches (110-130 mm typical) |
| Drilling Method | Percussion and rotation combined |
| Compatible Hammer Size | 4-inch DTH hammer (e.g., COP44, DHD340A, QL40, SD4) |
| Applications | Mining, quarrying, water well drilling, geotechnical, construction |
| Core Material | High-strength alloy steel |
| Cutting Surface | Tungsten carbide buttons (spherical or ballistic) |
| Energy Source | Compressed air (10–25 bar range) |
How Does a 4 Inch DTH Hammer Drill Bit Work
DTH (Down-The-Hole) drilling differs from top hammer systems in that the percussion mechanism is located directly behind the bit, minimizing energy loss.
Here's how it works:
Compressed air flows through the hammer, activating an internal piston.
The piston impacts the bit shank, transferring percussive energy directly to the rock.
Rotation from the drill rig turns the bit, allowing the carbide inserts to cut and crush the rock.
Air exhaust flushes rock cuttings from the hole, maintaining penetration speed.
This method is highly efficient for deep hole drilling because most of the energy is applied at the bottom of the hole - not lost along the drill string.
Key Features of a 4 Inch DTH Hammer Drill Bit
1. Optimized Diameter for Versatile Applications
A 4-inch diameter is ideal for medium-to-large boreholes used in blasting, anchoring, and exploration drilling. It strikes a balance between penetration rate and hole size, making it a standard across quarries and construction sites.
2. Tungsten Carbide Inserts for Longevity
The bit's buttons are made from tungsten carbide, one of the hardest materials on Earth.
Spherical buttons resist wear and maintain shape in abrasive rock.
Ballistic buttons provide faster penetration in softer formations.
3. High-Alloy Steel Body
The bit body is crafted from heat-treated alloy steel, offering superior fatigue resistance and tensile strength. This ensures long life even under repeated high-pressure impacts.
4. Air Flushing Efficiency
Optimized air holes improve cuttings removal, reducing bit regrinding and keeping the drilling face clean for faster progress.
5. Hammer Compatibility
These bits are precisely machined to fit 4-inch hammer models like:
DHD340
QL40
SD4
COP44
Mission40
Applications of 4 Inch DTH Hammer Drill Bits
| Industry | Application Examples |
|---|---|
| Mining | Deep-hole drilling, production blasting, exploration boreholes |
| Construction | Foundation piles, anchor holes, slope stabilization |
| Quarrying | Bench drilling, rock fragmentation |
| Geotechnical Engineering | Soil testing, core sampling |
| Water Well Drilling | Boreholes in hard formations |
The versatility of the 4-inch bit lies in its adaptability to various formations - from soft sedimentary layers to ultra-hard granite.
Specification
LEANOMS
Technical Parameters Of QL40 DTH Bits
| Diameter |
Gauge Buttons |
Front Buttons |
Weight(KG) |
Part Number |
||||
|
mm |
Inch |
Flat Face |
Convex Face |
Concave Face |
Face Type |
|||
|
115 |
4 1/2 |
Φ14*7 |
Φ14*2 |
Φ14*4 |
/ |
Convex Face |
9.6 |
LR-QL40-115CV-1 |
|
115 |
4 1/2 |
Φ16*7 |
Φ14*2 |
Φ14*4 |
/ |
Convex Face |
9.6 |
LR-QL40-115CV-2 |
|
115 |
4 1/2 |
Φ14*8 |
Φ14*2 |
Φ14*4 |
/ |
Convex Face |
9.6 |
LR-QL40-115CV-3 |
|
125 |
4 15/16 |
Φ14*8 |
Φ13*3 |
Φ14*4 |
/ |
Convex Face |
10.2 |
LR-QL40-125CV |
|
127 |
5 |
Φ14*8 |
Φ13*7 |
/ |
/ |
Flat Face |
10.3 |
LR-QL40127FF |
|
130 |
5 1/8 |
Φ14*8 |
Φ14*7 |
/ |
/ |
Flat Face |
10.5 |
LR-QL40-130FF |
Expert Insights: Trends and Technical Opinions
Dr. Helena Ortiz, Rock Mechanics Specialist, Mining Technology Review:
"The 4-inch DTH system has become the preferred standard for mid-depth mining and construction drilling. Its combination of high penetration rate and hole accuracy makes it a cost-effective solution in most geological environments."
A 2024 industry survey from Global Mining Analytics revealed:
72% of contractors using DTH bits reported lower operational costs.
Penetration rates improved by 15–25% compared to traditional rotary drilling.
Bit replacement intervals increased by up to 35% with improved tungsten carbide designs.
Scientific Data: Field Performance Study
| Parameter |
Conventional Bit |
4-Inch Leanoms DTH Hammer Bit | Improvement |
|---|---|---|---|
| Average Penetration Rate (mm/min) | 120 | 175 | +46% |
| Energy Efficiency (%) | 72 | 88 | +22% |
| Average Bit Life (holes drilled) | 280 | 410 | +46% |
| Hole Deviation (per 20m) | 10cm | 4cm | -60% |
(Source: Mining Equipment Performance Research Group, 2023)
Real-World Case Studies
Case 1: Limestone Quarry, Vietnam
A quarry using LEANOMS 4-inch DTH bits achieved a 32% faster drilling rate and reduced air consumption by 15%. The bits lasted through three blasting cycles before replacement.
Case 2: Gold Mine, South Africa
In high-pressure underground drilling, LEANOMS bits showed zero button loss after 200 hours of drilling in abrasive quartzite - outperforming a competitor's bit by 25%.
Case 3: Infrastructure Project, UAE
Foundation drilling through basalt achieved 20% straighter holes and required two fewer bit changes per shift, saving both time and labor.
User Feedback
Mark D. (Geotechnical Engineer, Canada): "Our penetration rate jumped by 25% after switching to LEANOMS 4-inch bits. The carbide wear pattern was minimal even after 300 meters."
MIcheal Y. (Mining Contractor, America): "Stable performance and zero shank breakage - that's what I call a dependable bit."
Samir A. (Project Manager, UAE): "We tested multiple brands, but LEANOMS provided the longest lifespan and cleanest hole finish."
Maintenance Tips for Longer Bit Life
Inspect Carbide Buttons Regularly: Replace worn or chipped inserts early to avoid uneven wear.
Monitor Air Pressure: Maintain the recommended range (10–25 bar) for optimal hammer performance.
Clean the Air System: Moisture and debris in air lines can reduce hammer impact efficiency.
Lubricate the Hammer: Use quality rock drill oil to minimize friction between internal components.
Rotate Bits Between Shifts: Helps balance wear and prolong total service life.
FAQs: Common Google Searches About 4-Inch DTH Hammer Drill Bits
1. What is a 4-inch DTH hammer drill bit used for?
It's used for drilling medium-to-large holes in rock or soil for mining, quarrying, construction foundations, and exploration drilling.
2. Which hammer fits a 4-inch bit?
Compatible hammers include DHD340, QL40, SD4, and COP44 models, depending on the manufacturer's connection design.
3. How deep can a 4-inch DTH bit drill?
With proper air pressure and a stable rig, it can reach up to 200 meters, depending on rock type and bit condition.
4. How can I extend the lifespan of my DTH bit?
Maintain correct air pressure, avoid dry drilling, and rotate bits regularly. Use a reliable supplier like LEANOMS for quality assurance.
Conclusion
From the first hammer strike to the final meter of depth, the DTH Hammer Drill Bit defines power, precision, and productivity.
Its efficient impact mechanism, durable carbide inserts, and universal hammer compatibility make it the preferred choice for modern drilling professionals.
So the next time your rig faces granite, basalt, or limestone, remember -
The right bit doesn't just drill faster; it drills smarter.
Choose LEANOMS DTH Hammer Drill Bits for reliability that cuts through challenges - one strike at a time.
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