Usual preface, I’m with PreciseBits so while I try to only post general information take everything I say with the understanding that I have a bias.
I’m with Winston here. There’s not really such a thing as a “standard” tool. Downcut is one aspect of tool geometry (helix direction). There are tons of other ones like:
- Rake: Angle of attach of the flute
- Helix angle: How tight the helix is
- Margin: One of the ways the back of the flute is ground
- Relief: another of the ways that the back of the flute is ground
- Core: The amount of material left after grinding flutes
- Core taper: Change in the core across the length of cut
- Flute volume: The amount of room in the flute for chips
There are a lot more than that. Those will change how a tool cuts, the force to make the cut, the amount the tool will deflect, the finish of the cut, usable RPM, etc.
On top of that there is also the grade of the carbide used. And it’s not even close to as simple as “sub-micron”. To give you a rough idea here’s the listed specs of a number of sub-micro grain carbides that are in the K20 ISO spec:
-
Chinese YG7
T.R.S= 1.9GPa HRA=90
Kennametal KFS06
T.R.S.=3.44GPa HRA=93.3
Ryotec (Mitsubishi) TF15
T.R.S.=4.0GPa HRA=91.0
Those will not deflect, wear, or finish remotely the same.
One of the issues is that almost no one is going to tell you most of those features as it could let someone copy their tool. So in general you only get the bare minimum (number of flutes, helix direction, tip, micron “grade”).
If you want some examples of how some of these change the cut I go into it a little here:
Hope that’s useful. Let me know if there’s something I can help with.