forja

Forja is a metalworking process and the workshop where metal is shaped by plastic deformation, typically after heating to forging temperatures. It encompasses techniques that alter the shape and mechanical properties of metal through compressive forces, distinguishing itself from metal casting or machining. In a broader sense, a forja can also refer to the place where such work is carried out, i.e., a blacksmith’s shop or a dedicated forging shop.

Etymology and history: The term forja derives from Latin fabrica, meaning a workshop or craft. Forging has ancient roots, with early smiths heating metal and hammering it to produce tools, weapons, and components. Over centuries, forjas adopted increasingly specialized equipment, enabling higher strength parts and mass production.

Methods and types: Forging is commonly conducted as hot forging, where the metal is heated above its recrystallization temperature to improve ductility, or cold forging, done at ambient temperatures for high-strength parts. Subtypes include open-die forging, where the workpiece is compressed between two flat surfaces, and impression-die or closed-die forging, which uses shaped dies to produce near-net shapes. Techniques such as upsetting, drawing, and elongation are used to achieve final geometry. Post-forging operations may include trimming, finishing, and heat treatment.

Equipment and workflow: A typical forja includes a furnace or forge, hammer or press, anvil (bigorna), and hand tools such as tongs (tenazes) and hammers (marretas). Modern forjas employ hydraulic or mechanical presses, induction heating, and automated tooling to increase repeatability and production rates.

Applications: Forging produces components for automotive, aerospace, tooling, energy, and construction industries. Forged parts often exhibit superior strength and toughness compared to cast counterparts, making forging a core process in many engineering applications.