A DTH drilling rig (Down the Hole Drilling Rig)uses compressed air to drive a hammer directly at the bottom of the hole. The hammer strikes the bit repeatedly, breaking rock into small pieces. The same air blows the cuttings up and out. This method delivers straight, deep holes even in granite and basalt. These rigs are commonly used for blast holes, rock anchors, and drainage holes in open-pit mines, quarries, road construction, and foundation work. They save time and improve hole accuracy. If you need a reliable DTH drilling machine for your business, contact YG Machinery for more details and a custom quote.
Specifications for YG DTH Drilling Rig
| Model | YGK130 | YGK150 | YGK153 | YGK300 |
| Drilling Depth | 25m | 30m | 35m | 40m |
| Max Drilling Diameter | 130mm | 150mm | 225mm | 275mm |
| Power | 37kW | 45kW | 55kW | 70kW |
| Working Pressure | 0.7~2.4MPa | 0.7~2.4MPa | 0.7~2.4MPa | 0.7~2.4MPa |
| Air Consumption | 9~13m³/min | 10~15m³/min | 12~18mm³/min | 15~22mm³/min |
| Weight | 3400kg | 5900kg | 6300kg | 8000kg |
| Dimension (mm) | 6500×2110×2400 | 6500×2110×2400 | 6680×2110×2500 | 7600×2350×2800 |
How does the DTH Drilling Machine Work?
The working principle of a DTH drilling rig is straightforward. An air compressor sends high-pressure air down the drill pipe. The air reaches the hammer at the bottom. Inside the hammer, a piston moves back and forth very fast. Each forward stroke hits the drill bit. Each backward stroke opens an exhaust port. The bit transfers the impact energy to the rock. The rock cracks and breaks. Meanwhile, the rotation mechanism turns the whole drill string slowly. This ensures the bit contacts fresh rock with every strike.
The operator controls the feed force from the surface. Too much feed slows the hammer. Too little feed reduces drilling speed. The crawler DTH drilling machine uses a hydraulic cylinder to push the drill pipe down. The same hydraulic system lifts the pipe when the hole is finished. After each blow, the exhaust air rushes out of the hammer. It travels up the gap between the drill pipe and the hole wall. This air carries rock chips to the surface. The operator can see the cuttings and know what rock type lies below.
Advantages of a Portable Drilling Rig
1. Fast penetration in hard rock
The hammer hits the bit directly at the bottom. No energy loss along a long steel rod. This direct impact makes a DTH drilling rig 1.5 to 2 times faster than top hammer rigs in granite, basalt, and other hard formations.
2. Straight and accurate holes
The hammer stays centered inside the hole. The drill pipe does not bend under load. Hole deviation is less than 1 percent over 30 meters. This accuracy means fewer wasted explosives and better blast patterns. It also makes anchor installation more reliable.
3. Low operating cost
Few moving parts in the hammer. Daily maintenance takes 15 minutes. Fuel consumption is about 0.4 liters per meter drilled. Compare that to rotary rigs, which burn more fuel and need frequent bit changes.
4. Works in wet conditions
Water in the hole does not stop the hammer. The high-pressure air blows water and rock cuttings out together. Other drilling methods struggle when the hole fills with water. A DTH drilling rig keeps working through wet seams and underground springs.
5. One rig, multiple hole sizes
Change the bit and hammer. The same machine drills holes from 90mm to 275mm. Small holes for rock anchors. Large holes for quarry blasting. You do not need to buy a second rig when the job changes. Just swap the tools and keep drilling.
6. Simple transport
The crawler drives onto a low-bed trailer by itself. No disassembly needed for most road moves. The machine arrives at the next site ready to drill in minutes.
Where to Use a DTH Drilling Rig?
- Open-pit mining: Blast holes need a consistent diameter and depth. The DTH drilling machine delivers both. Mines use the YGK150 and YGK153 for production drilling in iron ore, copper, and gold.
- Quarrying: Granite, limestone, and marble quarries use this rig for bench drilling. The YGK130 is popular for smaller operations. The YGK300 handles large diameter holes for dimension stone.
- Road and tunnel construction: Mountain highways require rock anchors and drainage holes. The crawler rig works on slopes where wheeled machines cannot go.
- Foundation drilling: Large buildings and bridges need rock sockets for piles. The DTH method gives clean holes with straight walls. No casing needed in stable rock.
- Urban excavation: City construction sites need low noise and low vibration. The DTH drilling rig produces less surface disturbance than blasting. It works next to existing buildings.
Get the DTH Machine Price from YG Machinery
YG Machinery is a manufacturer of drilling equipment. We produce crawler DTH drilling rigs, portable drilling rigs, and water well drills. Our machines have been exported to Saudi Arabia, Brazil, Peru, Chile, South Africa, the United States, and many other countries. Fast shipping available. If you need a reliable DTH drilling machine for your mining or construction project, contact YG Machinery today. Please tell us your rock type, hole depth, and diameter. We will recommend the right model and send you a quote within 24 hours.
