... φ110, φ130, φ160, φ170, φ219, φ27514. Chinese Standard Metric Core Bits for Double Tube Core Barrels: φ56, φ59, φ75, φ9115. Chinese Standard ... Metric Core Bits for Wireline Core Barrels: φ59, φ75, φ91We can manufacture all kinds ... of i diamond core drill bits and reaming shells according to customer's special requirement. PDC core bit for AQ BQ NQ NQ3 ...