Skip to content

Interrupted Numbering

Interrupted Numbering.  Numbering out of sequence; serial numbering with gaps in sequence.  See serial numbering.

The inner aperture of this coining collar shows a blank area between areas where reeding has been machined into the collar wall. This creates the edge of a struck piece using this collar in a coining press. It will have a plane edge where the blank area without reeding is located and two areas with. Note lettering on the collar indicates this is for a 50mm (2-inch ) coin, dual blank areas – called “bars” here -- and the date it was made. Any number of blank with reeded areas is called interrupted reeding. Photo: Medallic Art Company.

Interrupted Reeding. Struck from a collar with one or more smooth areas on the inner wall of the collar alternating with the reeding. This is in contrast to a piece which is fully reeded forming a REEDED EDGE, or completely smooth forming a PLANE EDGE. When only one smooth area is formed, this is generally at the bottom or top edge so edge marking can be placed there at some later time. See EDGE LETTERING AND NUMBERING.

The mass, the diameter and hardness of the collar must be great enough to sustain the pressure of constant use in production coining.  Width and diameter of the collar must fit the chuck of the coining press for it to be locked into position. The reeding is formed with a drift pin driving into the aperature of a prepared collar. See REEDING EDGE.

In 1965 the Franklin Mint developed a method of interrupted reeding that provided gambling tokens of similar diameter with edge distinctions to identify different casino's tokens by the edges when stacked in columns or laid out in rows. Pairs of blank and reeded areas, plus different width of reeds give this distinction. A separate collar with unique blank and reeded areas provided this when pieces were struck in this collar. It was granted patent number 3350802 in 1967 for this type of reeding.

CLASS 10.2

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators


Roger W. Burdette, Editor

NNP is 100% non-profit and independent // Your feedback is essential and welcome. // Your feedback is essential and welcome.