Cast Iron Columns

Cast Iron Columns. . , The Iron City , For much of the 19th century, Pittsburgh was known as the Iron City. Home to large and small iron mills and foundries, the region produced a diversity of iron products including nails, cannon, structural and sheet iron, as well as a variety of cast pieces. Iron was king, and companies such as the Sligo Iron Works, Oliver Iron, Carnegie Brothers, and the American Iron Works (later Jones and Laughlin Steel), pictured below, found great success in the region.

Making of Cast Iron , Cast iron is made by re-melting pig iron in a small furnace, called a cupola. The quality and use of the finished cast iron are dependent on the quality of the pig iron. Historically, some of the poorer qualities were only suitable for crude castings such as sash weights, while the better ones were suitable for the manufacture of items such as engines, columns, and girders. Molten iron is into metal frames, forms, or boxes containing sand into which an impression of the cast item has been formed using a wooden pattern.

Cast Iron , First introduced as a framing material in the 1830s, cast iron allowed architects and builders to have a viable alternative to masonry load bearing walls. Cast iron, being relatively lightweight and strong, made the construction of taller and slimmer buildings such as high-rises possible. Cast-iron columns, compared to masonry columns, had the advantage of being slender and strong which saved space in factories, shops, arcades, and other kinds of buildings. However, it was also notoriously brittle, prone to cracking, and often inconsistent in its makeup. By the early 20th century, these problems, along with the reliable production of wrought iron and steel, relegated cast iron to purely decorative uses such as the columns located at this site.

McKnight Hardware Columns , The columns located here were from the McKnight Hardware Co. located on the corner of Federal Street and W. Lacock Street on the North Side, pictured on right. The building, opened in 1878 by Samuel McKnight (1853-1919), stood until it was razed as part urban and highway development on the North Side. According to architectural historian Walter Kidney, "columns such as these were used to support the interior floor structures of medium-size commercial and public buildings in the middle and late 19th century. The floor structure itself was usually of wood."