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How to Choose DTH Drill Bit?
Aug 15, 2018



The types of DTH drill bits on the market are now exquisite, and the manufacturers of the drills also have their own rhetoric. Fortunately, it is not easy for a dealer who does not know how to find a high-quality and low-cost drill product. So the question is, how should we choose the DTH drill bit? 


DTH drill bits are mainly divided into two series with high air pressure and low air pressure. Adopt high quality raw materials and adopt advanced production technology. Widely used in earth and stone works, mining, water well drilling, construction and so on.


DTH drill bits currently have four types of end face design: end face convex type, end face flat type, end face concave type and end face deep concave center type. Carbide is mostly made of ball teeth, spring teeth or ball teeth and spring teeth.


Face Design.jpg


1. Face Convex Type: This kind of drill bit is divided into two forms, single boss and double boss end face, the latter mainly used for larger diameter.


DTH drill bit. The face-faced type of down-the-hole drill bit can maintain a high rock drilling rate when drilling hard and hard abrasive rock, but the straightness of the borehole is poor, and it is not suitable for rock drilling with high blast hole flatness. engineering.


2, Flat Face Type: This shape of the drill bit is more durable, suitable for drilling hard and extremely hard rock, but also suitable for drilling medium and hard rock and soft rock with low flatness.


3. Concave surface type: This shape has a conical concave part on the end face of the bit. It is a bit of nucleation during the rock drilling process to maintain the alignment performance of the drill bit. The drill hole has a good straight line. Degree, this drill bit has good drainage effect and fast drilling speed. It is a dTH drill bit that is used more on the market.


4. End face deep concave center type: This type of drill bit is evolved from the same type of ball tooth bit, and the center end of the end face of the drill bit has a deep concave central portion. It is used for nucleation during rock drilling and ensures the straightness of the blasthole when drilling deep holes. It is only suitable for drilling soft rock and medium hard rock.


DTH drill bit instructions


In order to properly use the down-the-hole drill bit and ensure the drilling speed and service life of the drill bit, the following points must be noted:


1. Select the down-the-hole drill bit according to the rock condition (hardness, abrasion) and the type of rig (high wind pressure, low wind pressure). Different forms of alloy teeth and cloth teeth are suitable for drilling different rocks. Choosing the right DTH drill bit is the prerequisite for optimal use;


2. When installing the down-the-hole drill bit, the drill bit should be placed gently into the drill bit of the down-hole impactor card. Do not force the collision to avoid damage to the drill bit or the card holder;


3. During the rock drilling process, it is necessary to ensure that the pressure of the downhole drilling rig is sufficient. If the impactor is interrupted, or the blasthole is not well discharged, the compressed air system of the downhole drilling rig should be inspected to ensure that there is no slag in the hole during the drilling process;


4. If metal objects are found to fall into the hole, they should be sucked out by magnets or taken out by other methods in time to avoid damage to the drill bit;


5. Pay attention to the size of the drill hole that has been drilled when replacing the drill bit. If the diameter of the drill bit is excessively worn, but the blast hole has not been drilled, the new drill bit cannot be replaced to avoid sticking.


Although the difference in the appearance of the down-the-hole drill bit can be distinguished in appearance, the drilling product still needs to select the drill bit according to the actual drilling conditions.


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