1. DTH Hammer suffers from the limitation of the aperture. The small diameter and large length result in poor rigidity and low hardness. It is prone to shock, ripple and taper during cutting, which affect its straight line and rough appearance.
　　2. When drilling and reaming, the cooling type is not easy to input to the cutting position without special equipment, so that the tool resistance is reduced, and chip removal is also very difficult.
　　3. When making deep holes, it is not possible to directly check the cutting condition of the tool. Only listen to the sound of the cutting condition and the instrument based on the construction experience to distinguish whether the cutting is normal.
　　4. Chip discharge is not easy. Use credible means to implement chip breaking and control the type of chip to help smooth discharge and prevent chip clogging.
　　Different geology, apply different models of DTH Hammer
DTH Hammer plays a major role in large mountains or formations with high rock content. Its function can form shallow pile holes on the surface. The rocks are blown and sunburned in nature, and complex geological and crustal changes occur. Diversity and vast land, so the object of DTH Bit work is particularly complicated. Often divided into the following categories.
According to rock properties, there are various lithological drill bits such as mud and shale model bits, sandstone model bits, and granite model bits; according to the origin of the rock, they can be divided into magmatic rock model bits, sedimentary rock model bits, and metamorphic rock model bits; according to Newtonian physical mechanics It is divided into solid rock, plastic rock and looser rock.
　　 We can choose drill bits of different models and uses according to the nature of the stratum structure.
　　 (1) Clay layer: Rotary drill bit with single layer bottom, weathered rock: Cone core drill-cone type auger.
　　(2) For mud, soil, and pebble layers that are not highly viscous, double-deck bottom augers are often used.
　　 (3) Hard clay: a rotary drilling bucket with a single inlet.
　　 (4) Frozen soil layer: You can choose the combination of bucket tooth auger and rotary drill bucket, and use conical auger for high degree of freezing.
　　(5) Strongly weathered rock: conical auger, or a combination of augers with double bottom for household use. Various situations can be changed according to different situations.