AE2

"Ae2" is a name given to medium-sized Roman bronze coins for which the original name is unknown. The name simply comes from the Latin noun for bronze or something made of bronze, "aes". The suffix "2" denotes the size of the coin, with "1" being the largest and "4" being the smallest. The assignment of the numbers is via a somewhat arbitrary scale, with no standard dominating.  Size in reference to coinage must take into consideration both diameter and weight, and hence the renowned authority John P.C. Kent proposed in 1994 the following system in Volume X of "The Roman Imperial Coinage":
                                         Ae       Diameter               Weight
                                          1      over 21 mms       over 10.0 gms
                                          2      19-21 mms          4.0-10.0 gms
                                          3      14-18 mms          1.5-4.0 gms
                                          4      below 14 mms      below 1.5 gms

A coin is considered to be in the lowest number class for which either its diameter or weight qualify it.\ Thus a coin weighing 11 grams may be considered an "Ae1" although it is only 20 mms.

The primary application of the above system is to fourth and fifth century Roman bronze coinage, of which little is known from contemporary sources.  However, it is technically correct to apply the term to any Roman bronze (and by popular extension, brass), and hence sestertii (see "Sestertius") can be referred to as "Ae1's", although that is today considered an odd application of the term.  The terms first, second, and third brass were formerly used in a sense similar to, but not exactly like, the "Ae" system and are today considered antiquated.

Since "Ae" is a Latin diphthong, the term is occasionally rendered in ligature ("Æ" or "æ"). The MONETA program uniformly uses the non-ligate form since standard computer sortation puts the ligate forms at the end of the standard alphabet instead of at the front where most would look for them.