Large Diameter DTH Hammers
- Applicable hole diameter: 305-1200mm
- Thread connection types: NUMA 120/180/240; API REG
- Material: low-carbon alloy steel
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The large-diameter DTH hammer is characterized by excellent operational stability and extended service life, and has achieved a market share of over 70% in China. These hammers are specifically designed for complex geological conditions such as karst cavities, cobble and gravel layers, boulder formations, and slightly weathered bedrock. They are widely used in: Embedded installation methods for precast piles, CFA (continuous flight auger) rock-socketed piles, bored piles drilled into rock
Typical Applications
Technical Specifications
| Item | |
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| Length without bit | 1698.5mm | 1954mm | 1954mm | 2543.5mm | 2529.5mm |
| Weight without bit | 551kg | 894kg | 1493kg | 2598kg | 3990kg |
| Hammer OD | 275mm | 330mm | 406mm | 525mm | 645mm |
| Bit shank | DHD112 | PWD14 | NUMA180 | PWD24 | PWD28 |
| NUMA120/125 | NUMA125 | NUMA240 | NUMA280 | ||
| SD12 | - | - | - | ||
| Recommended hole diameter | Ø305-Ø400mm | Ø400-Ø500mm | Ø500-Ø650mm | Ø650-Ø800mm | Ø800-Ø1000mm |
| Thread connection (top sub) | API6 5/8" REG | API7 5/8" REG | HEX | HEX | HEX |
| Max. working pressure | 3.5MPa | 3.5MPa | 3.5MPa | 3.5MPa | 3.5MPa |
| Impact frequency | 18bar, 23Hz | 18bar, 22Hz | 18bar, 18Hz | 18bar, 16Hz | 18bar,12Hz |
| Recommended rotation speed | 15-40r/min | 15-40r/min | 10-25r/min | 5-15r/min | 2-8r/min |
| Air consumption | 18bar, 70m³/min | 18bar, 85m³/min | 18bar, 110m³/min | 18bar, 130m³/min | 18bar, 145m³/min |