Maraging steel is the hardest metal on Earth. This steel is an alloy of nickel, cobalt and molybdenum. Most of the hardest metals are not naturally occurring; instead, they are man-made alloys.
Maraging steel is very difficult to deform, and even once it is fractured, it takes a great deal more force to break it fully. It is also strong against pulling forces. Most of the strongest metal alloys include nickel, carbon and chromium in their composition. Nickel-based super alloys often include these ingredients and are strong even at extreme temperatures, making them a perfect option for jet engines and turbine blades.