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Helical vs Fluted End Mills
- Thread starter cg 2005
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Tom Griffin
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All end mills have helical flutes, unless you are talking about the carbide insert types. Can you post a pic showing the end mills you are referring to?
Tom
Tom
I am thinking that you may be thinking of parabolic vs helical.
Your photos show a high helix, commonly used for aluminum, and a regular helix. Thus both are helical end mills. Not as common, but still available and useful, are straight flute end mills, sometimes called "keyway mills". A straight fluted mill will produce better slot or keyway geometry than a helical mill. It alleviates the "sloping slot" syndrome. It also will not tend to pull out of the collet, or pull the work up. A helical mill cuts smoother, due to the fact that there is always at least one flute engaged in the cut, where the straight flute mill tends to pound, due to the fact that the cut is somewhat interrupted.
Regards
Bob
a helical cutter uses shear cutting action which is smoother and continuous as opposed to a straight fluted cutter. a straight (single) flute cutter doesn't grab and lift the material though and is also easier to sharpen in the shop (or can be ground with a form in it as well to cut irregular shapes)
both pictures you posted are helicals though. a "fluted" (or straight) cutter looks like this:
both pictures you posted are helicals though. a "fluted" (or straight) cutter looks like this:
Not my terminology. The terms come directly from a retailer. They distinguish between the end mills as depicted.
technically, the geometry difference between the 2 is that what is referred to as "helical" has a steeper angle to the helical flutes resulting in a more shear action during the cut, and more cutter contact with the workpiece as opposed to the "fluted" cutter which has a more shallow angle to the helical flutes. this results in a cleaner more rigid cut made by the "helical" cutter as opposed to the "fluted" cutter but also create a higher pulling force by the cutter on the workpiece. these 'helical' cutters are best used for finishing (light) cuts and will produce a better surface finish.