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Analysis of the four end face designs of DTH drill bits, how much do you know
DTH drill bits, especially high-pressure DTH drill bits, currently have four main end face designs: convex end face type, flat end face type, concave end face type, and deep concave end face center type. In terms of tooth arrangement, cemented carbide usually uses ball teeth, spring teeth, or a combination of the two for configuration.
Mar 27th,2025
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Analysis of the four end face designs of DTH drill bits, how much do you know
DTH drill bits, especially high-pressure DTH drill bits, currently have four main end face designs: convex end face type, flat end face type, concave end face type, and deep concave end face center type. In terms of tooth arrangement, cemented carbide usually uses ball teeth, spring teeth, or a combination of the two for configuration.
1. Convex end face type
This type of DTH drill bit is divided into two types: single boss and double boss end faces, the latter of which is often used for down-the-hole drill bits with larger diameters. When drilling medium-hard and hard abrasive rocks, it can maintain a high rock drilling speed, but the straightness of the drill hole is relatively poor, so it is not suitable for rock drilling projects with strict requirements for blasthole straightness.
2. Flat end face type
This drill bit is designed to be sturdy and durable, and is particularly suitable for drilling hard and extremely hard rocks. At the same time, it is also suitable for drilling medium-hard rocks and soft rocks with low requirements for blasthole straightness.
3. Concave end face type
This type of DTH drill bit is designed with a conical depression on the end face, which helps to form a slight nucleation effect during the rock drilling process, thereby maintaining the centering performance of the drill bit. The blastholes drilled by it have good straightness, excellent powder removal effect, and fast drilling speed. It is a type of down-the-hole drill bit widely used in the market.
4. Deep concave center end face type
The DTH drill bit evolved from the same type of ball tooth drill bit, and a deep concave center is designed at the center of its end face. It is mainly used for nucleation during rock drilling to ensure the straightness of the blasthole when drilling deep holes. However, it is only suitable for drilling soft rock and medium-hard rock.
