3‑Blade Concave PDC Drag Bit
🔄 Rotary Drilling
⌀ 75‑325 mm
High Stability · Strong Center Cutting · Smooth Cuttings Removal
Concave Geometry · Center‑Cut Dominance
The 3‑Blade Concave PDC Drag Bit is specially engineered for rotary drilling in soft to medium formations (F<8). Its unique concave blade profile eliminates the “center dead zone”, allowing central cutters to engage rock first. This design delivers faster penetration, superior guidance, and exceptional hole straightness.
⛏️ Coal / Soft shale
🪩 Limestone (soft)
3‑wing · Concave
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1. Enhanced Center Cutting
Thanks to the concave blade, central PDC cutters engage first. As a result, it eliminates the center dead zone, reduces torque fluctuation, and boosts the rate of penetration (ROP) in homogeneous formations.
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2. Superior Guidance & Stability
The natural guiding profile reduces radial vibration and improves hole verticality. This design minimizes deviation risk, making it ideal for straight, precise boreholes.
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3. Smooth Cuttings Removal
The concave cavity, large junk slots, and optimized hydraulics work together to ensure fast debris evacuation. Consequently, there is no mud balling, allowing for safer and more continuous drilling.
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4. Durable & Cost‑Effective
High‑quality PDC cutters and balanced load distribution protect outer cutters. This leads to longer life and a lower cost per meter.
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5. Wide Adaptability + Custom
We offer over 10 standard sizes, adjustable cutter density, concave depth, and thread types. Additionally, we can custom‑engineer the bit to match your rig and formation.
✅ Recommended Applications
- ✔ Gas drainage & pressure relief holes
- ✔ Grouting & anchoring holes
- ✔ Shallow water wells
- ✔ Geological exploration
- ✔ Slope anchoring & foundation reinforcement
- ✔ Rapid hole construction projects
🪨 Suitable Formations (F<8)
Mudstone
Coal seams
Soft shale
Soft limestone
⚠️ Not recommended
This bit is not suitable for granite, basalt, or other extremely hard or highly abrasive formations. For formations with a hardness of F>11, please ask about our impregnated bits.
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Standard Bit Diameters (mm)
91
113
133
153
171
200
220
245
275
300
325
Custom diameters and concave depth are available upon request.
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Thread Options
REG Thread:
2 7/8″
3 1/2″
4 1/2″
NC Thread:
NC26
NC31
NC38
Other Types:
Z-50 Thread
Custom connections
🔧 Provide a thread drawing for full customization
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Drilling Method & Circulation
This bit is designed for rotary drilling. We recommend using it with mud or clean water circulation. Proper cooling and cuttings removal will significantly improve efficiency and bit life.
📌 Your Customization Expert
If your thread is not listed, or if you need a special concave depth or different cutter density, send us your drill rod spec or formation data. Our engineers will propose the optimal concave PDC solution within 24 hours.