sentence: Carbon steel is harder but more brittle.
sentences_before: Steel is the most common form of iron. Steels come in several forms. Mild steel is steel with a low percentage of carbon. It is soft and easily bent, but it does not crack easily. It is used for nails and wires.
sentences_after: It is used in tools. There are many other types of steel. Stainless steel does not rust. Other steels are very hard.
concept_name: carbon steel
headings: Iron Uses As a metal