The corrosion of 3S-0 and 52S-0 aluminum, AISI 347, and 321 stainless steels, "A" nickel, and low-leaded brass has been determined from the weight change of specimens exposed alternately to liquid and gaseous fluorine. Experiments were continued for a total exposure time up to 3 1/2 months. It was found that corrosion is negligible under the conditions of the experiments. No visual differences were observed between those surfaces exposed to the gaseous phase only and those exposed to both the liquid and the gaseous phases.