Four and More Flute HSS End Mills

 Flute HSS End Mills

Multiple flutes provide a number of cutting surfaces to spread the cutting force. Having four or more flutes adds rigidity while dispersing the chip load allowing for heavier feed.

Non-center cutting end mills can be resharpened by grinding the face of the flute on a tool and cutter grinder. 
HSS Center Cutting End Mills
Center cutting end mills can be used for spot drilling, profiling and contouring of complex surfaces.