Description

in the hole range *****4 mm (3"**0"), DTH drilling is the dominant drilling method today (especially when the hole depth is greater than *0 meters). The main features of DTH drilling in this hole range are:
• Excellent hole straightness within 1.5% deviation without guiding equipment.
• Good hole cleaning with plenty of air for the hole cleaning from the hammer.
• Good hole quality with smooth and even hole walls for easy charging of explosives.
• Deep hole drilling capacity with constant penetration and no energy losses in joints.
• Efficient energy transmission.
• The disturbance to the ground is kept minimum, and for drilling rock, the penetration rate is outstandingly high. 
• More cost-effective than the conventional rotary drilling.