The 40 years history of manufacturing diamond bits by electroplating has been seen in our country There are good drilling
properties in drilling rocks by
electroplated diamond bit because room temperature of producing them is no harm to diamond and Nickel base matrix has excellent mechanical properties But the electroplated diamond bit has poor ability in the bit gauge, especially in drilling hard, brittle and fractured rocks. In this paper, the new manufacturing technics including the bits with the double tapered working surface, the spiral water slots and semi bottom spurt, protecting diameter by polycrystalline diamond gauge, electroplating inner and outer cylindrical surface and electroplating lip surface separately, electroplating by moving the dies and electroplating
Nickel Cobalt Manganese alloy matrix to improve the ability of protecting gauge of electroplated diamond bit, which help to enlarge the drilling scope of electroplated diamond bits and promote their developoment, are analyzed and compared. Lab and field test show that the service life of electroplated diamond bit of Nickel Cobalt Manganese alloy matrix, whose diameter is protected by polycrystalline diamond, will be improved by 30%.