| 摘要 |
A method for forming a rotary cutting tool 300 having a polycrystalline-diamond (PCD) cutting tip (22 figure 1), the method comprising of forming at least two generally axially extending coolant passages 312 in a generally cylindrical tool body 302. Forming at least two coolant passages 308 in the tip portion 304, the passages extend between a work face and rear face of the tip portion. The tip portion is machined separately from the tool body and then coupled to the tool body with the respective coolant passages in the tool body and tip portion aligned. The tip portion can be coupled to the tool body via a brazing process to form the rotary cutting tool with at least two generally axial channels therethrough.. Further independent claims include a rotary cutting tool with an elongate body disposed about a longitudinal axis (A-A fig.1), the body including a helical flute (32 fig.1) and a PCD cutting tip. The cutting tip includes a work face with an inner axially projecting point portion (50 fig.1) having an inner point angle (Υ fig.1) and an outer shoulder portion (52 fig.1) having an outer point angle (Γ fig.1) different from the inner point angle Υ. |
