The primary material used in cast iron pans is, as the name suggests, cast iron. Cast iron is a type of iron that contains carbon, silicon, and manganese, with varying amounts of other elements. The carbon content is typically between 2% and 4%, which gives cast iron its characteristic hardness and durability. The process of casting involves pouring molten iron into a mold, which is then allowed to cool and solidify, resulting in a pan with a thick, even layer of iron on the cooking surface.

The use of cast iron in cookware is advantageous for several reasons. Firstly, cast iron is highly durable and can last for generations with proper care. It is also excellent for even heat distribution, which is crucial for cooking methods that require consistent temperatures, such as slow cooking or searing. Additionally, cast iron is non-reactive, meaning it does not impart flavors into food, making it versatile for a wide range of recipes.

According to a study published in the Journal of Food Science, cast iron cookware can retain heat for longer periods than other materials, which is beneficial for maintaining the temperature of dishes during cooking. This property is particularly useful for recipes that require precise temperature control, such as baking or frying. Furthermore, the natural non-stick surface that develops on cast iron over time is free from harmful chemicals found in traditional non-stick coatings, making it a healthier option for cooking.

In summary, cast iron is the primary material used in cast iron pans due to its durability, even heat distribution, and non-reactive nature. These characteristics make it an excellent choice for a wide range of cooking methods and recipes, contributing to its enduring popularity among home cooks and professional chefs alike.