split mold

A mold is a cavity used in manufacturing to shape fluid or plastic substances into finished products. These substances, like molten metal or plastic, are poured or forced into the mold and then allowed to harden. Molds can be made from various materials, including sand for metal casting, hardened steel for plastics, and plaster.1

The concept of casting, where liquid metal takes the shape of a mold, was a significant advancement from the Stone Age. Early molds were simple impressions in clay or sand, evolving to more durable stone cavities. The development of two-piece, or split, molds was particularly beneficial for casting bronze, as it expanded slightly before solidifying, capturing mold details effectively. This technique allowed for the creation of more complex shapes than were possible with earlier materials like copper.23