CORE DRILLING TOOLS
The reaming shell connects the diamond bit to the core barrel outer tube, maintains hole gauge and stabilizes the drilling assembly. Outside diameters are 75.7 mm for NQ, 96.1 mm for HQ and 122.6 mm for PQ.
NQ 75.7 mm · HQ 96.1 mm · PQ 122.6 mm
A conventional reaming shell sits immediately behind the diamond bit at the lower end of the outer tube. The bit cuts rock and forms the core; the shell maintains hole diameter and supports the lower drilling assembly. They perform different jobs.
Shell diameters are 75.7, 96.1 and 122.6 mm for NQ, HQ and PQ; corresponding bit diameters are 75.3, 95.6 and 122.0 mm. The shell gauge is slightly larger than the bit. Keep the bit, shell and barrel model consistent.
Wear of the shell outside diameter reduces its gauge-holding and stabilizing function. Check wear with the appropriate gauge when changing a bit or retrieving the assembly, rather than judging the diamond surface alone. Order the shell separately in NQ, HQ or PQ.
| Model | Outside diameter mm |
|---|---|
| NQ | 75.7 |
| HQ | 96.1 |
| PQ | 122.6 |
| Model series | NQ / HQ / PQ |
|---|---|
| Position | Between the bit and outer tube |
| Main functions | Maintain hole gauge, stabilize the assembly, connect the bit and outer tube |
Values are for equipment selection; supplied configurations follow the quotation and equipment documents.
No. The bit cuts the rock and forms the core. The shell behind it maintains gauge, stabilizes the assembly and connects the outer tube. Match both to the same model.
NQ is 75.7 mm, HQ 96.1 mm and PQ 122.6 mm. These are shell gauge diameters, not core diameters.
Diamond core bits
NQ / HQ / PQ
NQ / HQ / PQ series
Tube systems, assemblies & accessories
Core barrel tubes · sold separately
NQ / HQ / PQ · 1.5 m / 3 m · separate supply