Leaded bronze

Leaded bronze is an alloy of copper and tin, with a small proportion of lead added. The lead improves castability and metal flow compared to standard bronze and can make striking or finishing easier, but it also tends to reduce toughness and can affect long-term surface stability. Leaded bronze typically has a brown to reddish-brown appearance and develops a patina over time. Leaded bronze was mainly used for low-denomination coinage in the Roman Empire.