Hi Les, the birds mouth bits have cutting edges at an angle on each cutting edge.
The angle allows you to route angles on the edges to enable the construction of rounded, or cone shaped items. I have the bits from Lee Valley and they work fine.
I constructed a waste basket, out of some cherry stock with them and had to sand the out side surface round, but that was easy because very little material was left proud of the surface. The idea was originally used to make masts for ships.
Woodnut65 |