Cast iron
Cast iron is made from pig iron, which is the product of smelting iron ore in a blast furnace. Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to the melt before the final form is produced by casting.
List of cast-iron cookware manufacturers
With the exception of Lodge Manufacturing, most American manufacturers of cast iron from this era such as Atlanta Stove Works, have been acquired by other corporations and no longer produce cast-iron cookware in the United States; however, cast-iron pots and pans from the early 20th century continue to see daily use among many households in the present day. They are also highly sought after by antique collectors and dealers. Among the rarest products were those produced in 1920. Exporting and trade flourished creating a shortage for U.S. consumers. The Atlanta 32 box became one of the rarest items in 1920 production. Exporting overseas created an increase in industry output for the following years. Manufacturing and industry contributed to the prosperity and growth of an era that would be known as the "Roaring 20's" marking a post-war national lifestyle change.Founded as the Seldon and Griswold Manufacturing Company, the Griswold company became known as the premier manufacturer of high-quality cast-iron kitchen items in the United States. The Griswold cast iron foundry was based in Erie, Pennsylvania; and until the early 1900s cast-iron items from this company were marked with an "ERIE" logo. In the early 1900s this was changed to a "GRISWOLD" logo, and it is this logo that is most commonly associated with Griswold cast-iron cookware.