Milled coinage in 1890. In modern practice in the United States, milling, or a milled edge, can refer to the raised edge on the coin face, applied by a special milling machine after the planchets are cut out and polished. In addition, the reeding of coins of higher value, applied by the collar holding the coin when it is stamped, can be considered part of the milled edge. Milled coinage In numismatics, the term milled coinage (also known as machine-struck coinage) is used to describe coins which are produced by some form of machine, rather than by manually hammering coin blanks between
Metal roof since they have approximately the same appearance and workability. Metal roof A metal roof is a roofing system made from metal pieces or tiles characterized by its high resistance, impermeability and longevity. It is a component of the building envelope. Zinc, copper and steel alloys are commonly used. Copper has played a significant role in architecture for thousands of years (see: copper in architecture). In the 3rd century B.C., copper roof shingles were installed atop the Lovamahapaya Temple in Sri Lanka. The Romans used copper as roof covering for the Pantheon in 27 B.C. Centuries later, copper and its alloys