| 摘要 |
<p>This method is particularly suited for practice on a multiple spindle screw machine in which each work spindle carries a length of bar stock. The work end of each bar is formed, mixed and drilled in a conventional manner to form thereon a wheel shaped workpiece which is then rotated between two thread dies to form diagonal grooves in its periphery. The work is then subjected to two successive breaching operations which out grooves transversely of the lands formed by the threading dies. When the work has entered the bore of the second breaching tool, the tool is related slightly relative to the work to upset the teeth so that their sharp cutting edges are caused to face outwardly.</p> |
