... credit . 2.Approve ICQ inspection& obtain UKAS certification PDC core bit with (include any size and oversize)China Drilling Geological ... plug water swivel overshot outer tube & inner tube wrench foot clamp etc5. P- Gauge Core Bits: PQ, PQ3, PWF-Long, PWF ... 130, φ160, φ170, φ219, φ27514. Chinese Standard Metric Core Bits for Double Tube Core Barrels: φ56, φ59, φ75, φ9115. Chinese Standard Metric ...