Rock Drilling Tools
The concentric three-wing casing drilling system is suitable for soft to medium formations such as clay, flowing sand, small gravel, and highly weathered rock (f ≤ 3).
Typical applications include overburden drilling for water wells, anchor cables, and similar projects.
| Model | O.D. of casing tube, mm | I.D. of casing tube, mm | Thickness, mm | Guide device max. diameter, mm | Reamed diameter, mm | Min. O.D. of casing shoe, mm | Quantity of blocks | DTH hammer | Weight, kg |
| | 108 | 94 | 7 | 92 | 117 | 86 | 85 | 3.5'' | 10 |
| | 114 | 101 | 6.5 | 99 | 125 | 91 | 90 | 3.5'' | 12 |
| | 127 | 108 | 9.5 | 106 | 138 | 99.5 | 98 | 3.5'' | 14 |
| | 146 | 125 | 10 | 123.5 | 155 | 117 | 115 | 4'' | 25 |
| | 168 | 148 | 10 | 146 | 180 | 138 | 136 | 5'' | 37 |
| 168 | 153 | 7.5 | 146 | 185 | 142.5 | 141 | 5'' | 38 | |
| | 178 | 158 | 10 | 156 | 192 | 148 | 146 | 5'' | 42 |
| | 183 | 163 | 10 | 161 | 196 | 153 | 151 | 5'' 6'' | 46/50 |
| | 194 | 174 | 10 | 172 | 206 | 162 | 160 | 6“ | 58 |
| 194 | 181 | 6.5 | 179 | 206 | 170 | 168 | 6“ | 62 | |
| | 219 | 199 | 10 | 196 | 237 | 187 | 185 | 6“ | 72 |
| 219 | 207 | 6 | 205 | 237 | 192 | 190 | 6“ | 74 | |
| | 245 | 225 | 10 | 222 | 263 | 210 | 208 | 8'' | 106 |
| | 273 | 253 | 10 | 251 | 305 | 241 | 239 | 8'' | 132 |
| 273 | 257 | 8 | 255 | 305 | 241 | 239 | 8'' | 134 | |
| | 325 | 304 | 10.5 | 302 | 350 | 282 | 280 | 8'' 10'' 12'' | 205/220/240 |
| Other specifications are available upon request. | |||||||||
- The center pilot bit provides excellent guiding performance. Compared with other drilling systems, borehole deviation is significantly reduced. Even thin-wall steel casing or PVC casing can be used safely, greatly reducing the risk of casing breakage.
- The three reaming jaws are positioned on the same horizontal plane, enabling full-circumference rock breaking and significantly reducing the risk of tool jamming.
- The jaws operate along a vertically oriented sliding track. Even if small amounts of sand or cuttings enter the gap between the jaws and the pilot bit, vibration generated during drilling helps clear the material quickly, effectively reducing sticking and jamming incidents.
It is typically used where high borehole verticality is required and the formation is relatively hard or contains larger gravels.
It is suitable for most formations. For highly complex formations with frequent cavities or very deep oil and gas wells, a concentric casing drilling system with ring bits is recommended.
The three-wing system performs well in relatively complex formations, provides reliable rock-breaking capability, and is simple to operate, making it a popular choice among users..

