Matt Ring Tube Sizer
Enlarge the finger size of wax models evenly and accurately.
Hardwood mandrel that's been specially machined to incorporate a steel cutting blade that extends from the handle to the tapered tip.
Slide this tool through the hole in the wax ring tube and rotate clockwise.
The embedded steel blade will scrape the inner wall to enlarge the hole to desired size that is clearly marked, leaving a smooth finish.