I have been in a lot of camshaft places----both flat tappet and rollers cams are made out of both cast or steel billet cores----some even get a narrow groove ground in them and them welded with hard facing stellite like blacksmiths used to put on plow shears---
ain't it nice to know that stellite is used for things from the walking speed of a mule team all the way up to the fastest internal combustion engines