End mills- 2 flute or 4 flute?

End mills do not have cutting teeth across all of the end, but have a 'dead' area in the centre, and thus can only be used for milling using the side of the

End mill Diameter is 1 ~ 25, less than 1mm, often referred to as micro-diameter end mill, such as ~ mm in diameter Larger than 20mm

difference between port and slot End Mills are used for making shapes and holes in a workpiece during milling, profiling, contouring, slotting, counterboring, drilling and reaming

difference between slot drill and end mill This video covers a detailed discussion on the major differences between Drilling and End