The Numismatics including understands the round North and mittelitalische cast Ace - copper coins series of the 4th and 3rd century BC. The common characteristic of these coins is usually a value mark, for example the Roman one (I) as the basic denomination as well as images of gods or often the Prora . The standard weight ( coin base ) of the Aes grave coins was initially the Roman trading pound ( Libra ) of the equivalent of 327.45 grams - later the weight reduced by 2 ounces from around 272 to the uncial weight of around 10 to 12 grams for a copper As of the imperial era. The value ranges from As to Uncia and the rare half and quarter ounce. There were also multiple aces.
In numismatic literature, the similar designation Ae (Æ) generally stands for late Roman ( Follis ) copper or bronze coins, the exact designation of which is partly unknown today. The designations Ae 1 to Ae 4 are approximate coin size specifications in modern coin catalogs (AE1 = 32-26 mm, AE2 = 25-21 mm, AE3 = 20-17 mm, AE4 = <17 mm).
- Italo Vecchi : Italian Cast Coinage. A descriptive catalog of the cast coinage of Rome and Italy. London LAC 2013, ISBN 978-0-9575784-0-1 .
- Ernst Justus Haeberlin : Aes grave. The heavy money of Rome and Central Italy including the raw bronze currency that preceded it. Frankfurt 1910.
- Rudi Thomsen : Early Roman Coinage. A Study of Chronology. Copenhagen 1957/61.