To compare the performance of HASTELLOY C-22 alloy with that of other materials, it is useful to plot the 0.1 mm/y lines. In the following graphs, the lines for C-22 alloy are compared with those of two popular, austenitic stainless steels (316L and 254SMO), and a lower-molybdenum nickel alloy (625), in hydrochloric and sulfuric acids. The tests in hydrochloric acid were limited to a concentration of 20% (the azeotrope). At hydrochloric acid concentrations above about 5%, C-22 alloy provides a quantum improvement over the stainless steels, and offers much greater resistance hydrochloric acid than 625 alloy in the concentration range 8 to 20%.