Dave Plowman (News) wrote:
For cutting a hole in plywood, what is the name of the best type of router
cutter to use?

A spiral flute up or down cutter depending on which face need to be
perfect. Down cut= good top face.
These bits tend to be best run at very high speed with steady feed as
found on CNC routers.
The bits are long lasting but expensive and intolerant of problems-
being made of solid tungsten carbide.
Depending the work and the user a single flute straight cutter might
work out better value for DIY use? These give adequate top and bottom
finish with a carbide blade supported by a tough steel shank.