Archeologists say iron was first used in tools as early as 2,500 B.C. in what they call the Bronze Age. Once refining techniques were improved, iron became relatively inexpensive; however, iron’s main disadvantage over bronze was that it rusted when wet. This meant, taking a modern example, that cutlery made of iron or steel had to be washed and dried immediately after use, otherwise it would rust. It was clear to all that there was a need for a rust-less iron, that is, an inexpensive material that did not rust.