The durability of a metal sculpture in outdoor environments is heavily influenced by the type of metal used. Different metals react uniquely to weather conditions, affecting longevity and maintenance requirements.

Stainless steel is a popular choice due to its high corrosion resistance, especially grades like 316, which contain molybdenum for added protection against saltwater and acidic rain. Bronze, while prone to developing a patina, forms a protective layer that prevents further degradation, making it ideal for long-lasting sculptures.

Corten steel, or weathering steel, is designed to rust superficially, creating a stable outer layer that shields the core from further corrosion. However, untreated metals like iron or carbon steel will rust extensively without protective coatings, requiring frequent upkeep.

Aluminum offers lightweight durability and natural oxidation resistance but may lack the structural strength for larger pieces. Copper, like bronze, develops a verdigris patina over time, which can be desirable for artistic effects but may not suit all designs.

Ultimately, the metal choice balances aesthetics, environmental factors, and maintenance willingness. Proper sealing and occasional cleaning can extend the life of any metal sculpture, but selecting the right material from the start ensures lasting outdoor beauty.