Pull Boring
- Pull boring is a special configuration of counter-boring in which the tool cuts chips when it is pulled out of the workpiece.
- A special lantern
chuck may be used to adjust the pull bore tool at the work headstock end. The boring bar without the tool is passed through the existing workpiece bore until bar thread protrudes from the guide bushing in the lantern. The tool is then threaded on to the boring bar and pulled out of the workpiece as it bores the ID.
- Since the boring bar is in tension rather than compression, this method provides a better control over hole straightness.
- Multicutter pull boring cutters are used in boring of centrifugally cast tubing. These tools pilot off of the existing holes and thus maintain a uniform wall thickness.
- When used to straighten the hole, pull boring tool can be made to follow the center line of the machine by supporting off of the finished hole.
Machines with Pull Boring Capabilities:
