These alloys are commonly referred to as commercially pure (C.P.) titanium with the level of impurities and mechanical properties increasing slightly from ERTi-1 to ERTi-4. C.P. Grade 2 titanium (ERTi-2) is the most widely used titanium alloy for industrial applications because of its good balance of strength, formability and weld ability. Typical uses are in seawater and brackfish water heat exchangers, chemical process heat exchangers, pressure vessels and piping systems, pulp bleaching systems, air pollution control scrubbers and electrochemical and chemical storage tanks. This alloy is also used in the aerospace industry under AMS 4951 specification.