Countersink is a conical hole cut into a manufactured object;A common use is to allow the head of a bolt or screw, with a shape exactly matching the countersunk hole, to sit flush with or below the surface of the surrounding material. (By comparison, a counterbore makes a flat-bottomed hole that might be used with a hex-headed capscrew.) A countersink may also be used to remove the burr left from a drilling or tapping operation.
HSS CO Zero Flute Countersink
Angle 60 Degree, 82 Degree, 90 Degree, 100 Degree, 110 Degree, 120 Degree All available.
| Code | Thread | Dia | Shank Dia | Overal Length |
| 900COSC0104 | 1-4 | 6.35 | 6.35 | 45 |
| 900COSC0205 | 2-5 | 10 | 6 | 45 |
| 900COSC0510 | 5-10 | 14 | 8 | 48 |
| 900COSC1015 | 10-15 | 21 | 10 | 65 |
| 900COSC1520 | 15-20 | 28 | 12 | 85 |
| 900COSC2025 | 20-25 | 35 | 12 | 102 |
| 900COSC2530 | 25-30 | 44 | 15 | 115 |
| 900COSC3035 | 30-35 | 48 | 15 | 127 |
| 900COSC3540 | 35-40 | 53 | 15 | 136 |
| 900COSC4050 | 40-50 | 64 | 18 | 166 |