CF8 vs CF8M Valve Material
CF8 and CF8M are cast austenitic stainless-steel grades, with CF8M containing molybdenum and broadly corresponding to the chemistry associated with 316-type stainless steel.
That chemistry difference can matter in corrosive environments, but actual suitability also depends on process chemistry, chlorides, temperature, velocity, trim and fabrication conditions.
A valve material decision should be based on the complete service environment and project material specification rather than choosing CF8M solely because it is the higher-alloy option.