wootz

Wootz, also known as crucible steel, is a class of high-carbon steel that originated in the Indian subcontinent and Sri Lanka. It is renowned for its iron-carbide microstructure and the distinctive surface patterns that can appear when the metal is forged, patterns that later became associated with Damascus steel in the Islamic world. The carbon content of wootz ingots typically lies around 1 to 2 percent, and trace alloying elements from ore can influence carbide formation and hardness.

Production of wootz involved melting iron in a sealed crucible with carbon-rich materials such as plant charcoal. The liquid iron would absorb carbon from the surrounding material, then the crucible was cooled and the solid ingot hammered and worked to refine its structure. The resulting billet could be forged into blades with a unique combination of hardness and toughness. The specific methods varied by region and period, and many details of the ancient workflow remain partially debated.

Historically, wootz steel was produced in southern India and, to a lesser extent, Sri Lanka, and it was traded widely across the Indian Ocean. By medieval times, Damascus and other centers in the Middle East and Central Asia possessed blades said to have been made from wootz, contributing to the legendary reputation of Damascus steel. The technique declined with the rise of modern iron and steelmaking in the 17th–19th centuries, though interest in wootz and its patterns has persisted in metallurgical research and experimental recreation.

In modern studies, researchers examine wootz to understand carbide formation and diffusion in high-carbon steels. Reproducing authentic wootz remains challenging, and contemporary blades that imitate Damascus patterns often rely on different metallurgical approaches, such as pattern welding.