Roughing end mills (bellow left) have their flutes serrated to break chips thus reducing horsepower requirement.
Fast-spiral end mills (right) are used when machining relatively soft materials that will get hot easily. The design of this end mill allows for fast removal of the chip and reduces heat transfer to the work piece. Fast-spiral end mills are also called high-spiral end mills.
Ball nose end mills (right) are used when the work piece requires a 90 degree concave fillet or when machining a three dimensional surface (example: mold making).
Key slot cutters (right) are used to machine key-slots in shafts. The cutter shown is a Woodruff key cutter.
Corner rounding cutters (above left) are used to make a 90 degree convex radius on a work piece edge. Useful for esthetic removal of a sharp corner.
Dove tail end mills (right) are used to machine dove tail shapes in the work piece.
Concave cutters (left) can cut a full 180 degree arc on a work piece if
the work piece is the same width as the cutter. A convex end mill (right) can cut a perfect 180 degree U shaped groove.
The Vee shaped cutter (left) can cut a V shape into a work piece.
The T-slot cutter (right) is designed to cut slots similar to the slots in the top of a machine table