| 1. | If a hole is drilled, the pressure can be reduced in the hole and thereby in the rock section adjacent to the hole .
如果一个井孔钻成，井内压力就要下降，井孔附近岩体内的压力也跟着下降。 |
| 2. | Safety protection and control of deep well drilling
深孔钻的安全保护与控制技术 |
| 3. | Detachable pilots for counterbores and countersinks
扩孔钻和沉头钻用可拆卸导杆 |
| 4. | Tool inspection methods part 11 : core drills
刀具产品检测方法.第11部分:扩孔钻 |
| 5. | Root canal files and reamers , type k for hand use
手持k型牙根管锉和扩孔钻 |
| 6. | Arbors for shell reamers and shell core drills
套式铰刀和套式扩孔钻用心轴 |
| 7. | Arbor for tip type countersink drill . dimensions
片式沉孔钻用刀杆.尺寸 |
| 8. | Shell core drills with hard metal tips
镶硬质合金刀片的筒形扩孔钻 |
| 9. | Arbor for reverse countersink drill . dimensions
反沉孔钻刀杆.尺寸 |
| 10. | Straight flute drill with indexable inserts
可转位直沟浅孔钻 |
