... are distributed in the depth of diamond core drill bit's matrix series. The matrix layer of the ... 3.032, NMLC, NWG(NX), NWM, NWT, TNW4. H-Gauge Core Bits: NQ, HQ-RSG, HQ-3.830, ... , 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 ...