Four-Wing Concave PDC Drag Bit for Soft to Medium Hard Formations with Interlayers
The four-wing concave PDC drag bit is specifically designed for high-precision, long-life drilling in soft to medium hard formations (F<8) with occasional soft-hard interlayers. Featuring a cross-symmetrical concave four-wing structure and premium PDC cutters with reinforced center teeth, it provides excellent directional stability, enhanced center rock breaking capability, and superior impact resistance, enabling stable long-distance drilling while significantly reducing bit change and hole deviation costs.
Widely used in anchor holes, grouting holes, slope reinforcement, foundation support, gas drainage holes, water wells, shallow geothermal drilling, and other applications requiring high hole quality and durability.
Core Advantages
Superior Hole Accuracy & Directional Stability
Cross-symmetrical concave four-wing structure minimizes radial vibration, providing exceptional hole verticality and roundness. Effectively reduces hole deviation, perfect for anchor and grouting applications with strict hole quality requirements.
High Center Rock Breaking Efficiency
Concave blade design allows center PDC cutters to contact formation first, enhancing center rock breaking capability and avoiding drilling resistance caused by “center blank”. Provides faster penetration rate and more stable footage in soft to medium hard formations.
Enhanced Impact Resistance & Stability
Four-wing design evenly distributes cutting loads, providing better adaptability to slight formation interlayers, effectively reducing blade wobble and fracture risks. Ensures stable operation in complex conditions with superior durability compared to standard four-wing bits.
Smooth Cuttings Removal & Anti-Balling
Concave cavity combined with large cuttings grooves and optimized hydraulic channels allows cuttings to be quickly removed with circulating fluid, reducing accumulation and significantly minimizing bit balling and sticking risks, ensuring continuous efficient drilling.
Wear-Resistant & Extended Service Life
Premium PDC cutters with even distribution and concave protective structure ensure balanced force on blades and reduced wear rate per wing. Under similar conditions, offers longer footage than standard bits with extended service life and lower cost per meter drilled.
Wide Compatibility & Fully Customizable
Covers over 10 standard sizes with fully customizable thread types, cutter density, concave depth, and blade structure. Tailored solutions for different drilling rigs and specific project requirements.
Applications
Suitable Formations
Red sandstone, mudstone, coal seam, shale, limestone, marble, and other soft to medium hard formations.
Suitable for composite formations with occasional soft-hard interlayers.
Not recommended for extremely hard or highly abrasive formations such as granite or basalt.
Drilling Method
Rotary Drilling – Recommended to use with mud circulation or water circulation for efficient bit cooling and cuttings removal, improving drilling stability and extending bit life.
Product Specifications
Standard Bit Diameter (mm)
- 75 / 91 / 113 / 133
- 153 / 171 / 200 / 220
- 245 / 275 / 300 / 325
- Custom diameters and concave depth available
Thread Types
- REG: 2 3/8, 2 7/8, 3 1/2, 4 1/2
- NC: NC23, NC26, NC31, NC38
- Other: Z-50, Custom Threads
Customization Services
If your drill pipe thread is not listed above, simply provide thread parameters or drawings for a fully customized connection solution. We can also adjust cutter density, concave depth, and blade structure based on formation hardness to optimize rock breaking, cuttings removal, and impact resistance performance.
Our Manufacturing Excellence
From precision machining to final assembly — every drill bit is crafted in our ISO 9001 certified facility.
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