| 摘要 |
PURPOSE:To simply and surely polish the tip abrasion part of thread cutting blade of a spiral tap, by intermittently poslishing the tap in such a way that the tap is separated from a grinding wheel each time the polishing of one thread cutting part is completed. CONSTITUTION:With relatively arranging a grinding wheel 9 and a spiral tap 8 for inclining the axial line (1) of the grinding wheel 9 with respect to the axial line (m) of the tap 8 in the vertical direction so that the peripheral surface 10 of the grinding wheel 9 is made parallel with the end ridge line of a thread cutting blad 7 formed in the thread cutting part 6 of the tap 8, both 9, 8 are rotated in the opposie directions with respect to each other, and the tip of the cutting blade 7 of the tap 8 is polished by being pushed against the peripheral surface 10 of the grinding wheel 9. By separating the tap 8 from the grinding wheel 9 each time the pollishing of one cutting blade 7 is completed, the cutting blade 7 is intermittently polished. Thus, the polishing of tip abrasion part of the cutting blade which has been hitherto impossible, may be simply and surely made. |
