Cast-iron cookware
Because other cookware cleaning techniques like scouring or washing in a dishwasher can remove or damage the seasoning on a bare cast-iron pan, these pans should not be cleaned like most other cookware. Some chefs advocate never cleaning cast-iron pans at all; simply wiping them out after use, or washing them with hot water and a stiff brush. Others advocate washing with mild soap and water, and then re-applying a thin layer of fat or oil. A third approach is to scrub with coarse salt and a paper towel or clean rag.
Window shutter hardware
Cast Iron - the product extracted from iron ore. Iron oxide-rich ore is heated to a molten state in the presence of limestone within a large flask. Oxygen makes a chemical transition from the iron oxides to the calcium forming a "slag" which floats to the top of an increasingly iron-rich molten pool. When done, the bottom of the flask is opened and the iron pours out - historically into sand patterns to produce cast iron stoves and such, or into troughs on the foundry floor to form rough billets. The billets could be re-melted and cast into shapes at other foundries or could be hammered into wrought iron in forges. Good news is cast iron flows easily into molds and can be used to quickly form intricate articles from iron. The bad news is that cast iron is brittle and cracks rather than bends. Brittle because it is not pure iron - impurities are not completely leached from the ore and carbon from the heating fuel is absorbed into the iron pool. Quick cooling of the iron in a mold also increases brittleness – smaller, thinner pieces (like hinges) are usually more brittle than larger, heavier pieces (like machines) that "hold their heat" when poured and thus take longer to cool.