Maraging Steel Round Bar 250 is normally used for aerospace and military applications. 250 Maraging Steel is very high strength, low weight steel made from a carbon free iron-nickel steel blend. Hints of aluminum, titanium, cobalt, and molybdenum give higher strength and lower weight. 250 Maraging Steel is lighter and less strong compared to 300 and 350 due to lesser amounts of cobalt and titanium.