rautahiili

Rautahiili is a Finnish term whose precise meaning varies across historical sources. Literally translating as "iron charcoal" (rauta = iron, hiili = charcoal), it is generally used to describe charcoal employed in traditional ironworking. In some contexts rautahiili denotes a type of charcoal briquette marketed to smiths, while in others it refers to charcoal used as a reducing agent in bloomery or forge operations. Because the term is not part of standard modern metallurgy vocabulary, its definition is often dependent on the specific text or region.

Etymology and usage: The compound combines rauta and hiili, and may appear in Finnish alloying and smithing literature in a fused form as rautahiili. The lack of a single, authoritative definition means the term can indicate either fuel for forges or a branded product rather than a universal material.

Historical and contemporary status: References to rautahiili are relatively scarce and largely confined to historical or regional sources. In contemporary Finnish metallurgy and industrial chemistry, the term is largely obsolete, with more precise terms such as charcoal, coke, or briquettes used instead.

See also: Charcoal, coke, ironworking, smithing.