| 摘要 |
<p>A thread-cutting tool comprises a shank 10 for attachment to the spindle of a milling machine, the forward end portion of which shank is formed with a flat 12 recessed to provide a pocket for a flat cutting insert 11. The insert, which is triangular in this instance, has one edge formed with a line of threadform teeth of identical profile. The teeth project laterally for cutting engagement with a workpiece. The surface of the workpiece which is to be formed with a thread is mounted on the work-table of the machine and is moved in a circular path centred on the axis of the spindle to bring the said surface into engagement with the teeth of the insert. The spindle is rotated at such a speed that in one revolution of the workpiece in its circular path a uniform cut is made round the whole of said surface, the spindle and tool being moved axially by one thread pitch for each revolution of the workpiece and work-table.</p> |
