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 — delivering faster penetration, superior guidance, and exceptional hole straightness.
⛏️ Coal / Soft shale
🪩 Limestone (soft)
3‑wing · Concave
1. Enhanced Center Cutting
Concave blade lets central PDC cutters engage first — eliminates center dead zone, reduces torque fluctuation, boosts ROP in homogeneous formations.
2. Superior Guidance & Stability
Natural guiding profile reduces radial vibration, improves hole verticality, minimizes deviation risk — ideal for straight, precise boreholes.
3. Smooth Cuttings Removal
Concave cavity + large junk slots + optimized hydraulics → fast debris evacuation, no mud balling, safer and continuous drilling.
4. Durable & Cost‑Effective
High‑quality PDC cutters, balanced load distribution, concave protects outer cutters — longer life, lower cost per meter.
5. Wide Adaptability + Custom
10+ standard sizes, adjustable cutter density, concave depth, thread types — we custom‑engineer for your rig & 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
Granite, basalt, extremely hard or highly abrasive formations. For F>11, please ask for our impregnated bits.
Standard Bit Diameters (mm)
91
113
133
153
171
200
220
245
275
300
325
Custom diameters & concave depth available upon request.
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 thread drawing → full customization
Drilling Method & Circulation
Rotary drilling · Recommended with mud or clean water circulation.
Proper cooling and cuttings removal significantly improve efficiency and bit life.
📌 Your Customization Expert
Thread not listed? Special concave depth? Different cutter density?
Send us your drill rod spec or formation data — our engineers will propose the optimal concave PDC solution within 24h.