Tetsu

Tetsu is the Japanese word for iron, the chemical element with symbol Fe and atomic number 26. The kanji 鉄 denotes iron and appears in many iron-related terms. In Japanese, tetsu is the common on’yomi reading used in compounds, while kurogane is a traditional kun reading referring to iron or steel in older or literary contexts. The character is used broadly to indicate iron and iron-containing materials in everyday language.

Historically, ironworking reached the Japanese archipelago from the Asian mainland, spanning the late Yayoi period into the subsequent centuries. The traditional tatara iron-smelting method produced tamahagane steel, used for tools, implements, and famously for swords. From the 16th to 19th centuries, iron and steel production gradually shifted toward larger, more centralized operations as part of Japan’s broader industrialization. In modern times, iron is produced on an industrial scale from iron ore in blast furnaces and integrated into a wide range of steel products.

In contemporary usage, the character appears in numerous terms related to iron and steel, including 鉄道 (tetsudō, railway) and teppō (鉄砲, gun). It also appears in contexts such as nutrition, where iron content is described with expressions like 鉄分. The character 鉄 is the traditional form, with the simplified Chinese form 铁 used in mainland China. The kanji is formed with the metal radical and reflects its role as a symbol for one of the earth’s most essential metals.