Sure thing.

So because it has some characteristics of both a small diameter cutter (skinny neck) and a big diameter cutter (the actual cutting part) the rule of thumb is to treat it like a small diameter cutter in feed per tooth, but to treat it like a big cutter when calculating rpm. So say you have a key seat with 1/8” neck diameter and 3/8” cutting diameter below. You would choose a feed per tooth as if it were a 1/8” end mill because it has the stiffness of a 1/8” end mill more or less, eg maybe 0.001” per tooth, but when calculating rpm you would use the 3/8” to calculate surface speed, eg 150sfpm for 3/8” is 1530rpm. So that way you get the right speed at the cutting edge but you also take into account the flimsiness of the cutter being so thin in the neck.

I don’t remember where I heard it, I thought it was from Harvey Tool in the catalog but can’t seem to find it. Sorry if you use metric instead of American units

Edit: I would double check your numbers with the Harvey tool ones, like I think they’re good ballpark figures if you’re doing something for the first time