70 percent of aluminium ingots in the U.S. are cast using the direct chill casting process, which reduces cracking. A total of 5 percent of ingots must be scrapped because of stress induced cracks and butt deformation. Historical ingots Plano-convex ingots are widely distributed archaeological artifacts which are studied to provide information on the history of metallurgy. See also Bullion Gold bar Oxhide ingot Sycee, traditional Chinese ingots Tin ingot Bar stock Wafer etching References Further reading External links Casting (manufacturing) Metallic objects