The flanks of teeth of rack-type gear cutter used for cutting involute gear profiles are:

The drawing shows a machined shaft. The purpose of providing rounded grooves at $$M$$ and $$N$$ is to

In Whitworth quick return mechanism (used in shapers) the velocity of the $$ram$$ is maximum at

Reamers have usually even number of teeth so that the cutting forces on teeth are properly balanced.