Shank Adapters and Couplings
The shank adapter that takes the blow from the rock drill and the couplings that join rods in the string. Both are high-cycle fatigue items rather than wear items.
Features
- The shank adapter takes every blow from the percussion unit directly and is a scheduled replacement, not a repair item.
- Shank splines, striking face flatness and thread condition all have to be inspected; a flared striking face damages the piston.
- Couplings are available with and without a stop shoulder; the choice follows the drilling method and the rig's rod handling.
- Half-bridge and full-bridge coupling designs differ in how they handle bending loads in deviated holes.
- Correct thread greasing at every joint make-up is the difference between a coupling lasting a shift and lasting a month.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Thread designation | R32 / T38 / T45 / T51 | Must match the rest of the string. | |
| Coupling type | with stop shoulder / without | Follows the drilling method and the rod handling system. |