Mixing Cast Iron
The art of mixing certain proportions of different brands of iron to obtain castings of such quality as will best serve the purpose for which they are intended. Without a chemical knowledge of the actual ingredients needed for the production of a certain quality of iron, mixing cast iron must always remain in the realm of conjecture. True, there is much to be said in favor of the superior facilities for subsequent testing; but this gives no substantial data, and must always be repeated on every change of the materials employed. Late developments relating to the power of silicon to change the nature of cast iron has opened a way for a more intelligent system of mixing. See ANALYSIS; TESTING-MACHINE; SILICON; SOFTENERS; GRADES OF PIG IRON.