| 1. | Study on theory of drill rod with new type structure
一种新型结构钎杆的理论研究 |
| 2. | Rope thread extension steel bars for rock drilling
凿岩用波形螺纹连接钎杆 |
| 3. | Rock drilling equipment . hollow drill steels in bar form
凿岩钎杆用中空钢 |
| 4. | Rock drilling equipment - hollow drill steels in bar form
凿岩钎杆用中空钢 |
| 5. | Hollow hexagonal drill rods with taperd connection for rock drilling
凿岩用锥体连接中空六角形钎杆 |
| 6. | Hollow hexagonal drill rods with tapered connection for rock drilling
凿岩用锥形连接中空六角形钎杆 |
| 7. | Rod taper for detachable rock - bit
可卸式凿岩钎头用锥形钎杆 |
| 8. | Study on improving the service life of drill rods by magnetic treatment
磁处理提高钎杆服役寿命的研究 |
| 9. | Mf - speed rod shank adaptor
Mf接杆钎杆 |
| 10. | Drifting rod mf - speed rod
Mf接杆钎杆 |
