DHD Series DTH Bits

Down-the-hole drill bits for mining, quarrying and exploration drilling
DTH Bits
  • DTH Bits
  • DTH Bits
  • DTH Bits
  • DTH Bits
  • DTH Bits
  • DTH Bits
  • DTH Bits

SPM offers a complete range of DTH bits, precisely tailored for various drilling scenarios. Products feature large front flushing grooves combined with waist-flow designs to accelerate airflow, reduce wear, and enhance durability. Durable alloy steel is precision-machined and surface stress-treated, paired with highly wear-resistant alloy buttons, ensuring enhanced longevity and operational efficiency.

The DHD series bits comply with industry-standard specifications and are fully compatible with other brand DHD drill tools of the same model, offering flexible operational solutions for diverse equipment configurations. The following basic bit types are optimized for different rock characteristics and working conditions.

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Bit Head Designs
  • Convex (Ballistic Button) Design
    Convex (Ballistic Button) Design

    Features a skirt structure with alloy buttons for improved cuttings removal, faster penetration in clay layers, and reduced regrinding wear. Dual-row outer teeth fit drill bits ≥178 mm (7 inches). Suitable for hard, abrasive rocks and various formations, especially fractured or loose strata.

    Typical formations: Granite (220 MPa / 32,000 psi), Hard Limestone (200 MPa / 29,000 psi), Basalt (300 MPa / 43,500 psi)

  • Flat (Spherical Button) Design
    Flat (Spherical Button) Design

    Optimized for abrasive, very hard rocks, suitable for all formations, particularly high-silica abrasive layers.

    Typical formations: Granite (220 MPa / 32,000 psi), Hard Limestone (200 MPa / 29,000 psi), Basalt (300 MPa / 43,500 psi)

  • Flat-Edge Ballistic Button Design
    Flat-Edge Ballistic Button Design

    Combines spherical and flat ballistic buttons to balance wear resistance and rock-breaking capability, suitable for medium-hard and abrasive rocks, optimized for high-productivity drilling.

    Typical formations: Granite (220 MPa / 32,000 psi), Hard Limestone (200 MPa / 29,000 psi), Basalt (300 MPa / 43,500 psi)

  • Concave Design
    Concave Design

    Significantly improves borehole verticality and reduces deviation. Suitable for hard, abrasive rocks and all formations, especially fractured/loose strata and projects requiring high vertical accuracy, fitting drill bits >178 mm (7 inches).

    Typical formations: Granite (220 MPa / 32,000 psi), Hard Limestone (200 MPa / 29,000 psi), Basalt (300 MPa / 43,500 psi)

Buttons Types
    • Spherical Button
      Spherical Button

      For highly abrasive, extremely hard rock, wide adaptability.

    • Semi-Ballistic Button
      Semi-Ballistic Button

      For medium abrasive, hard rock, fast drilling speed.

    • Ballistic Button
      Ballistic Button

      For medium abrasive, medium-hard rock, fast drilling speed.

    • Sharp Button
      Sharp Button

      For soft rock, fast penetration, mainly for anchoring bits.

    • Flat Button
      Flat Button

      Protects bit diameter during deep-hole drilling or in operations requiring precise borehole size, reducing wear on the bit body.

Technical Parameters
SPM335 shank (DHD3.5, TD35 Hammers)
SPM335 shank (DHD3.5, TD35 Hammers)
SPM
P/N 		Diameter, mm Button configuration
(No. x dia., mm) 		Gauge angle, ° Flushing holes Approx. weight, kg
Outer Inner Front Cone Outer Inner Cone
Flat face-spherical buttons
335-90Q 90 8x13 7x12 35 2 5.8
335-95Q 95 8x14 7x12 35 2 5.9
335-100Q 100 8x14 7x13 35 2 6.1
335-105Q 105 8x14 8x13 35 2 6.3
Convex face-ballistic buttons
335-90D 90 6x13 3x12 2x12 45 20 2 5.8
335-95D 95 6x14 3x12 3x12 45 20 2 5.9
335-100D 100 6x14 3x13 4x12 35 20 2 6.1
335-105D 105 6x14 3x13 4x12 35 20 2 6.3
Flat face-gauge spherical & center ballistic buttons
335-90S 90 8x13 7x12 35 2 5.8
335-95S 95 8x14 7x12 35 2 5.9
335-100S 100 8x14 7x13 35 2 6.1
335-105S 105 8x14 8x13 35 2 6.3
Configuration: matched shank SPM335-19
SPM340 shank (DHD340A, DHD4 Hammers)
SPM340 shank (DHD340A, DHD4 Hammers)
SPM P/N Diameter, mm Button configuration
(No. x dia., mm)		 Gauge angle, ° Flushing holes Approx. weight, kg
Outer Inner Front Cone Outer Inner Cone
Flat face-spherical buttons
340-105Q 107 8x14 0 7x13 0 35 0 0 2 8.6
340-115Q 115 8x14 0 7x13 0 35 0 0 2 8.8
340-120Q 120 8x14 0 8x13 0 35 0 0 2 9
340-130Q 130 8x14 0 8x13 0 35 0 0 2 9.6
Convex face-ballistic buttons
340-105D 107 7x14 4x13 2x13 0 35 15 0 2 8.6
340-115D 115 7x14 4x13 2x13 0 35 15 0 2 8.8
340-120D 120 8x14 4x13 3x13 0 35 15 0 2 9
340-130D 130 8x14 4x13 3x13 0 35 15 0 2 9.6
Flat face-gauge spherical & center ballistic buttons
340-105S 107 8x14 0 7x13 0 35 0 0 2 8.6
340-115S 115 8x14 0 7x13 0 35 0 0 2 8.8
340-120S 120 8x14 0 8x13 0 35 0 0 2 9
340-130S 130 8x14 0 8x13 0 35 0 0 2 9.6
Configuration: matched shank SPM340-18
SPM350 shank (DHD350R, COP54, DHD5 Hammers)
SPM350 shank (DHD350R, COP54, DHD5 Hammers)
SPM P/N Diameter, mm Button configuration
(No. x dia., mm) 		Gauge angle, ° Flushing holes Approx. weight, kg
Outer Inner Front Cone Outer Inner Cone
Flat face-spherical buttons
350-130Q 130 7x16 0 7x14 0 35 0 0 2 15.7
350-140Q 140 7x16 0 7x14 0 35 0 0 2 16
350-152Q 152 8x16 0 8x14 0 35 0 0 2 17.8
350-165Q 165 8x16 0 9x16 0 35 0 0 2 18.2
350-178Q 178 8x16 0 9x16 0 35 0 0 2 19.8
Convex face-ballistic buttons
350-130D 130 7x16 4x14 3x14 0 35 15 0 2 15.7
350-140D 140 7x16 4x14 3x14 0 35 15 0 2 16
350-152D 152 8x16 4x14 4x14 0 35 15 0 2 17.8
350-165D 165 8x16 4x14 5x14 0 35 15 0 2 18.2
350-178D 178 8x16 4x16 5x16 0 35 15 0 2 19.6
Flat face-gauge spherical & center ballistic buttons
350-130Q 130 7x16 0 7x14 0 35 0 0 2 15.7
350-140Q 140 7x16 0 7x14 0 35 0 0 2 16
350-152Q 152 8x16 0 8x14 0 35 0 0 2 17.8
350-165Q 165 8x16 0 9x16 0 35 0 0 2 18.2
350-178Q 178 8x16 0 9x16 0 35 0 0 2 19.8
Configuration: matched shank SPM350-18
SPM360 shank (DHD360, COP64, DHD6 Hammers)
SPM360 shank (DHD360, COP64, DHD6 Hammers)
SPM P/N Diameter, mm Button configuration
(No. x dia., mm) 		Gauge angle, ° Flushing holes Approx. weight, kg
Outer Inner Front Cone Outer Inner Cone
Flat face-spherical buttons
360-152Q 152 8x16 0 11x14 0 35 0 0 2 23.5
360-165Q 165 8x16 0 10x16 0 35 0 0 2 25
360-171Q 171 9x16 0 10x16 0 35 0 0 3 25.8
360-178Q 178 8x16 0 11x16 0 35 0 0 2 27
360-194Q 194 9x16 0 12x16 0 35 0 0 3 29
Convex face-ballistic buttons
360-165Q 165 8x16 4x16 6x16 0 35 15 0 2 25
360-171Q 171 9x16 6x16 4x16 0 35 15 0 3 25.8
360-178Q 178 8x16 4x16 6x16 0 35 15 0 2 27
360-194Q 194 9x16 6x16 6x16 0 35 15 0 3 29
Flat face-gauge spherical & center ballistic buttons
360-171A 171 9x16 0 6x16 4x16 35 0 -15 3 25.8
360-178A 178 8x16 0 4x16 6x16 35 0 -15 2 27
360-194A 194 9x16 0 6x16 6x16 35 0 -15 3 29
360-203A 203 9x16 0 6x16 7x16 35 0 -15 3 35
360-216A 216 9x16 0 6x16 7x16 35 0 -15 3 36
360-219A 219 9x16 0 6x16 7x16 35 0 -15 3 37.2
360-230A 230 9x16 0 9x16 7x16 35 0 -15 3 40
360-241A 241 12x18 0 9x18 8x16 35 0 -15 3 46
360-254A 254 12x16 0 9x16 8x16 35 0 -15 3 50
360-300A 300 12x18 0 12x16 9x16 35 0 -15 0 58
360-305A 305 12x18 0 12x16 9x16 35 0 -15 3 64
Configuration: matched shank SPM360-19
SPM380 shank (DHD380M, DHD 8 Hammers)
SPM380 shank (DHD380M, DHD 8 Hammers)
SPM P/N Diameter, mm Button configuration
(No. x dia., mm) 		Gauge angle, ° Flushing holes Approx. weight, kg
Outer Inner Front Cone Outer Inner Cone
Convex face-ballistic buttons
380-203 203 8x18 0 6x18 6x16 35 0 -15 2 48
380-216 216 9x18 0 6x18 7x16 35 0 -15 3 49
380-219 219 9x18 0 6x18 7x16 35 0 -15 3 49.5
380-230 230 9x18 0 6x18 8x16 35 0 -15 3 50.8
380-235 235 9x18 0 6x18 8x16 35 0 -15 3 51
380-241 241 9x18 0 6x18 9x16 35 0 -15 3 51.9
380-245 245 9x18 0 6x18 9x16 35 0 -15 3 52.3
380-254 254 12x18 0 6x18 14x16 35 0 -15 3 54.5
380-273 273 12x18 0 9x18 12x16 35 0 -150 3 73.6
380-285 285 12x18 0 9x18 12x16 35 0 -15 3 77.2
380-300 300 12x18 0 9x18 12x16 35 0 -150 3 83
380-305 305 12x18 0 9x18 12x16 35 0 -150 3 84.6
380-311 311 12x18 0 9x18 12x16 35 0 -150 3 85
380-320 320 12x18 0 9x18 13x16 35 0 -150 3 88
380-325 325 12x18 0 9x18 13x16 35 0 -150 3 89.4
380-350 350 16x18 0 12x18 18x16 35 0 -150 4 92
Configuration: matched shank SPM380-19
Selection Guidance
  • High-efficiency scenarios: Convex / ballistic button design is preferred, with streamlined structure reducing drilling resistance and significantly increasing penetration speed.
  • Harsh formations: For high-hardness, strongly abrasive formations (e.g., quartzite, iron ore), flat spherical button bits offer durable teeth and robust structure, extending service life and reducing replacement frequency.
  • Strict quality requirements: For projects requiring precise verticality and smooth boreholes (e.g., pile foundations, anchor drilling), concave designs provide stable drilling trajectory and improved borehole quality.

Bit selection should consider rock hardness, abrasiveness, borehole precision requirements, and equipment compatibility. SPM ensures the equipment’s optimal efficiency and cost-effectiveness across all drilling conditions. Personalized selection guidance is available upon request.

The low air pressure series (working pressure 0.8-1.5 MPa) is recommended. Soft formations require lower impact energy for effective rock breaking. Low-pressure DTH hammers ensure sufficient penetration efficiency, reduced energy consumption, and slower tool wear. Medium- or high-pressure tools may cause excessive impact, increased cuttings pulverization, and higher risk of hole collapse, resulting in higher overall construction costs.

The large-diameter series is the preferred option. This series is engineered for large-diameter hole making and stable hole formation. Structural features include thicker tool walls for improved torsional strength and wider discharge channels to prevent cuttings blockage. Compatibility with high-torque output from pile-foundation drilling rigs ensures efficient, stable operation. Standard low- or medium-pressure tools may deform under load or suffer from inadequate cuttings discharge.

The medium air pressure series (working pressure 1.5-2.5 MPa) is suitable. Medium-pressure DTH tools deliver proper impact energy for medium-hard rock formations while matching the 1.8-2.2 MPa rig pressure range. Low-pressure tools provide insufficient impact, leading to slow penetration. High-pressure tools exceed the rig’s pressure capacity and cannot achieve normal performance.

Correct bit selection is essential.

  • Limestone (dense, hard rock): Use spherical-button DTH bits, which provide high wear resistance and concentrated impact points for efficient rock breaking.
  • Sand-gravel formations (loose formations with pebbles): Use flat-edge ballistic bits, which offer wider discharge grooves for rapid removal of gravel and reduced bit blockage.

Bit interfaces must match the selected DTH hammer connection standard, for example API REG threads, to ensure stable sealing and power transmission.

A medium air pressure DTH hammers paired with a composite-formation DTH bit such as a spherical-button can meet both layers’ requirements. Medium air pressure tools support efficient drilling in both sand layers and hard-rock layers. DTH bits with wear-resistant ballistic buttons and wide discharge grooves enhance cuttings removal in sand layers and improve rock penetration in hard rock.

When the lower hard-rock compressive strength exceeds 30 MPa, only the DTH hammer may be replaced with a high-pressure model while other components remain unchanged, reducing replacement cost.