Minnovation offer two diameters of trepanner tool ( as known in UK Coal "Tin Busters").
The trepanner tooling has been developed to create a smooth hole through the skin of corrugated sheet tin lining in an underground roadway for drilling & installing additional roof bolts without having to disturb the sheeting.
A small hole is penetrated through the tin sheet with the central carbide drill which then acts as a guide so the larger diameter hole can be formed by the larger diameter carbide edged coring portion.
Other diameters can be provided.
Click on images for more information.