You can search for "end mill cutting speed material". I typed this into duckduckgo.com and found this page, for example, http://www.etantdonnes.com/MACHINE/TABLES/cuttingSpeeds.html
Small radius cutters turn faster than large radius cutters to generate equivalent SFPM. A special package of different cutters that all turn at the same speed will ...
You should derive your speeds from the cutting speeds needed for the sizes of drill bits or cutting tool bit lengths to be used and the material being cut.
Some materials need slower speeds, others cut well at higher speeds so you should design for a suitable range not just copy another machine - they made their own decisions.