Stellite is an unusual material. It looks like high speed steel (HSS). It can be used in the same way as HSS. What is odd about it is that whereas HSS contains mainly iron alloyed with other metals such as nickel and chromium, stellite contains virtually no iron.
Sometimes it is marked “Stellite” but often that will have been lost. It can be distinguished from HSS easily by grinding it. It is conspicuously harder to grind than HSS is.