09-18-2015, 10:22 AM
The rigidity of any end mill isn't a matter of how many flutes it has. Rather it is the "core diameter" that affects its rigidity. Another big factor is flute length and how much of it is used. Another factor is the material it's made from. A HSS end mill will not be as rigid as a solid carbide end mill. The O.D. minus the flute depth is how you determine core depth.
The flute depth of an end mill, along with grinding angles and finish also affect how it performs in various materials. A lot of end mills are considered "general purpose", which is always a compromise on design. I have some three flute HSS-PM TiAlN-coated end mills designed for aluminum and they work exceptionally well for that material. I would never use them on anything except non-ferrous metals or plastics. I have other general purpose HSS uncoated end mills I use on a wide variety of materials, and some TiAlN coated solid carbide end mills I use on steels, stainless steels and other ferritic/martensitic materials. They all have various core diameters and I can see the differences based upon how I use them.
I still have much to learn!
The flute depth of an end mill, along with grinding angles and finish also affect how it performs in various materials. A lot of end mills are considered "general purpose", which is always a compromise on design. I have some three flute HSS-PM TiAlN-coated end mills designed for aluminum and they work exceptionally well for that material. I would never use them on anything except non-ferrous metals or plastics. I have other general purpose HSS uncoated end mills I use on a wide variety of materials, and some TiAlN coated solid carbide end mills I use on steels, stainless steels and other ferritic/martensitic materials. They all have various core diameters and I can see the differences based upon how I use them.
I still have much to learn!