There are four main types of end face design for DTH drill with high air pressure: convex end face, plane end face, concave end face and deep concave center end face. Cemented carbide can use ball teeth, spring teeth or ball teeth and spring teeth shared by the way of tooth.
1, convex face type: this kind of drill can be divided into two forms, single boss and double boss face, the latter is mainly used for large diameter DTH drill. When drilling medium and hard abrasive rocks, the convex type DTH drill bit can maintain a high drilling rate, but the flatness of drilling is poor, so it is not suitable for drilling projects with high requirements of hole flatness.
2, face plane type: this shape of the drill is more durable, suitable for drilling hard and very hard rock, but also suitable for drilling hole flatness requirements are not high in hard rock and soft rock.
3, end face concave type: this shape of the drill head end face has a conical depression part, is the formation of slight nucleation in the process of drilling to maintain the performance of the drill, drill hole has good straightness, this kind of drill powder effect is good, the drilling speed is fast, is used in the market more potential hole drill.
4, end face deep concave center type: this shape of the drill is evolved from the same type of spherical tooth bit, the center of the drill face has a deep concave center part. It is used for nucleation in the process of drilling, to ensure the flatness of the hole when drilling deep holes. It is only suitable for drilling soft rock and medium hard rock.
