HDD Drill Bits
SPM HDD drill bits are used with HDD hammer reaming systems for hard-rock horizontal directional drilling. After the pilot bore has been established, the bit works at the cutting face during bore enlargement, receiving impact energy from the hammer while the drill string rotates through the formation.
The available HDD bit sizes are 254 mm, 305 mm, 356 mm, 406 mm and 457 mm. These sizes correspond to the compatible bit range listed for the HDD hammer reaming system.
HDD drill bits are used for hard-rock bore enlargement in trenchless crossings for pipelines, utilities and other underground infrastructure. They are selected according to the required final bore diameter and the compatible HDD hammer reaming setup.
During bore enlargement, the drill bit is positioned at the cutting face of the HDD hammer reaming assembly. Percussive energy from the hammer fractures the rock while drill-string rotation distributes the cutting action around the bore, allowing the pilot hole to be enlarged to the required diameter.
Start with the required final bore diameter, then confirm the HDD hammer reamer configuration and drilling conditions. Rock hardness and abrasiveness should also be considered when matching the bit to the reaming system.