1.Using DTH hammer drilling is a good way to drill through cave formation and avoid stuck problem.
2.When encountering caves, drill bit inclines to the cave. You can add a stabilizer to ensure the hole straightness.
We can supply large diameter DTH hammers and bits with different shanks:
12”: DHD112, SD12, NUMA120, NUMA125
14”: NUMA125
18”: NUMA180
24”: NUMA240
PRODUCT NAME |
NUMA120 HAMMER |
BIT SHANK |
NUMA120 WITH FOOT VALVE |
CONNECTION THREAD |
API 6 5/8 REG |
MAX. WORKING PRESSURE |
30 BAR |
AIR CONSUMPTION |
70m³/min (18BAR) |
RECOMMEND ROTATION SPEED |
15-40 r/min |
OUTER DIAMETER |
275MM |
REC HOLE SIZE |
305-350MM |
LENGTH WITHOUT BIT |
1698.5MM |
WEIGHT |
550KG |
ITEM DESCRIPTION |
|
NO | PART LIST |
1 | TOP SUB (can insert carbides) |
2 | TOP SUB RING |
3 | CHECK VALVE |
4 | SPRING |
5 | SHOCK RING |
6 | CHECK VALVE GUIDE |
7 | AIR DISTRIBUTOR GUIDE |
8 | PRESSURE BEARING RING |
9 | AIR DISTRIBUTOR TUBE |
10 | PISTON |
11 | OUTER CYLINDER |
12 | BUSH DRIVE SUB |
13 | O RING |
14 | BIT RETAINING RING |
15 | STEEL RING |
16 | CHUCK SLEEVE |
PRODUCT NAME |
NUMA240 HAMMER |
BIT SHANK |
NUMA240 WITH FOOT VALVE |
CONNECTION THREAD |
HEX |
MAX. WORKING PRESSURE |
30 BAR |
AIR CONSUMPTION |
130m³/min (18BAR) |
RECOMMEND ROTATION SPEED |
15-25 r/min |
OUTER DIAMETER |
525MM |
REC HOLE SIZE |
500-1000MM |
LENGTH WITHOUT BIT |
2543.5MM |
WEIGHT |
2598KG |
ITEM DESCRIPTION |
|
NO | PART LIST |
1 | TOP SUB (can insert carbides) |
2 | TOP SUB RING |
3 | STEEL RING |
4 | CHECK VALVE |
5 | SPRING |
6 | SHOCK RING |
7 | CHECK VALVE GUIDE |
8 | O RING |
9 | AIR DISTRIBUTOR GUIDE |
10 | PRESSURE BEARING RING |
11 | O RING |
12 | AIR DISTRIBUTOR TUBE |
13 | PISTON |
14 | OUTER CYLINDER |
15 | BIT RETAINING RING |
16 | STEEL RING |
17 | CHUCK SLEEVE |
The large diameter bits are mainly used in three applications: embedded prefabrication pile, long spiral pile and large diameter end bearing pile.
The bit face mainly used concave face. The advantage of these face can ensure the straightness of the hole.
Bit shank | DHD112, SD12, NUMA120 |
Recommend hole size | 305-350mm (standard) |
Max. hole size | 580mm (oversized) |
Bit face | convex, drop center |
Material | alloy steel |
Button type | spherical, ballistic, semi-ballistic |
Button grade | YK05, KD10 |
Button installation method | cold pressing |
Bit shank | Numa180 |
Recommend hole size | 500-650mm (standard) |
Max. hole size | 770mm (oversized) |
Bit face | convex, drop center |
Material | alloy steel |
Button type | spherical, ballistic, semi-ballistic |
Button grade | YK05, KD10 |
Button installation method | cold pressing |
Bit shank | Numa240 |
Recommend hole size | 650-800mm (standard) |
Max. hole size | 1000mm (oversized) |
Bit face | convex, drop center |
Material | alloy steel |
Button type | spherical, ballistic, semi-ballistic |
Button grade | YK05, KD10 |
Button installation method | cold pressing |