One of the rarest and most
ingenious countersinks was patented on August 3, 1880 by
Daniel F. Barber.
It is a transformer tool and is the only tool I am aware of that
not only cuts a countersink but also serves as a dowel pointer.
Look and the photos and I think you will agree that Barber was a
This photo illustrates the Barber transformer tool in the
The slotted conical steel cutter readily cuts a countersink.
This photo shows a countersink cut by the bot in countersink