Surface Wireline Core Drilling Underground Wireline Core Drilling Multi-Purpose Drilling Reverse Circulation Drilling Directional Drilling Water-Well Drilling Grade Control Drilling Environmental Drilling Geotechnical Drilling Coal-Bed Methane - CBM Drilling Shallow Oil and Gas Drilling Standard Wireline Sizes Size Core Diameter Hole Diameter (inches / millimeters) AO-AQ-U 1.064 / 27.0 1.890 / 48.0 BQ-BQ-U 1.438 / 36.5 2.360 / 60.0 NQ-NQ-U 1.875 / 47.6 2.980 / 75.7 HQ 2.500 / 63.5 3.782 / 96.0 PQ 3.345 / 85.0 4.827 / 122.6 NQ-3 1.775 / 45.0 2.980 / 75.7 HQ-3 2.406 / 61.1 3.782 / 96.0 PQ-3 3.270 / 83.0 4.827 / 122.6 Thin Kerf Wireline Sizes Size Core Diameter Hole Diameter (inches / millimeters) AQ-TK 1.20 / 30.5 1.890 / 48.0 BQ-TK 1.601 / 40.7 2.360 / 60.0 AGM 1.193 / 30.3 1.890 / 48.0 BGM 1.654 / 42.0 2.360 / 60.0 NGM 2.248 / 57.1 2.980 / 75.7