Steel | GRHardnessTester.comSteel has been around for thousands of years and has proven a reliable structural material.  Steel is an alloy of carbon and iron and is one of the most common materials used for the framework of structures.  Strength and flexibility combined make up the best type of steel.  Steel can go from being soft to extremely hard and strong during phase transformations.  Damascus steel was a favorable steel used in ancient and medieval times for swords and knives.  It was strong, flexible, and could also hold an extremely sharp edge.

 

Click HERE for the full article by Walt Mills on Penn State.