Milling speed using a shell cutter

[Toolmaker51]

The formula for calculating RPM for HSS is (Cutting Speed X 4)/diameter
Memorize it, you will need it daily.
This is for HSS, carbide can be run 2-10 times faster.
Cutting speed for mild steel is 80-100 SFPM
Since I pay for my own cutters and no one is paying for my time, I use the conservative numbers.
(80x4)/2=160 for HSS
Double that for carbide =320 rpm.
These are numbers to get you in the correct range, they are not hard and fast.

In my 20 years in the trade, I NEVER calculated chip load or feed rate, that is mostly for CNC.
With a few exceptions, the power feed on manual mills is not graduated in IPM.
Start the feed slow and increase as your eyes and ears dictate.

I have that same cutter on an R8 shank.

All that is true, while rough per tooth estimates aren't too difficult. Lay a yardstick on the table, set a stop watch, and there you are. It only takes a few minutes to chart, what say "5" on a electric power feed relates to.
No penalty thinking like the Big Guys; many of us are equally "pay for my own cutters - without compensation", being too conservative is not a guarantee of less cutter wear; ejecting heat is.

Have mentioned more than caring to recall, hate this being referred to as a mere hobby. A smaller footprint, machines or resources is still doing same operations as the largest; and very likely how they began.
Except MESTA; they were probably immense day 1.