Why Use a Single Flute End Mill? - CNCCookbook: Be A ...
The answer is we space out more cutting edges (flutes) around the circumference of the cutter so that as the cutter is spinning, we get a lot more bites (chips) of the material. It's now pretty obvious. At a given surface speed, a 4 flute endmill can take 4 cuts at a given chip load (chip thickness) while a 2 flute only takes half as many.
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