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8. Die Links, Die Axis, AES Scale

Should coins be found that have been struck on the same obverse or reverse die, they are described as being "die linked". Coins sharing identical obverse and reverse dies are said to be "die duplicates". As described earlier, reverse dies wear out more rapidly than obverse dies, so obverse linked dies are more likely to be found than reverse linked dies.

Die Axis is a term used to describe the alignment between the two dies used to strike a coin. The die axes of thirteen Ostian minted coins are indicated below in Table 10 using the numbers on a clock face for reference. (Degrees are also used by some authors.)

The AES Scale is used to divide all bronze coins from the later issues (including those minted at Ostia) into one of four groups. The criterion used is the diameter of the coin in mm. And where coins are not perfectly round, the greatest diameter is measured.

AE1 25 mm. +
AE2 21-25 mm.
AE3 17-21 mm.
AE4 less than 17 mm.

Table 10: Die axes, reverse images, alignment of laurel wreath, mintmarks and AES types.

No.

Axis

Reverse Image

Upper part of laurel wreath pointing towards these letters in the inscription

Mintmark

AES type

1

12/6

Dioscuri

NT

MOSTP

2

2

12/12

Dioscuri

N

MOSTP

2

3

12/11

Dioscuri

T

MOSTP

1

4

12/12

Dioscuri

N

MOSTS

1

5

12/5

Dioscuri, she-wolf & twins

NT

MOSTA

2

6

12/6

Dioscuri

TI

MOSTS

1

7

12/6

Dioscuri, she-wolf & twins

NT

MOSTB

1

8

12/11

Dioscuri

NT

MOSTQ

2

9

12/11

A Genius

IN

MOSTT

2

10

12/5

Fides

NT

MOSTS

2

11

12/12

Dioscuri

T

MOSTQ

2

12

12/1

Dioscuri, she-wolf & twins

T

MOSTT

1

13

12/6

Fides

NT

MOSTQ

1


[et - 7-May-2005]