PART VI. Striking Errors:

Chain Strikes

Definition:  A chain strike occurs when two planchets, two coins, or a coin and a planchet lie right next to each other or abut one another within the striking chamber.  During the strike, the two expanding discs make contact where the original separation was narrowest.  The edges then flow together to form a line of contact whose length is variable.

While most chain strikes take the form of a straight edge, other shapes do occasionally appear.  Convex, concave, and sinuous chain strikes have been documented.  In some cases an indent lies alongside or is flanked by a chain-struck edge.

As one might expect, most chain strikes are associated with off-center strikes.  However, a subtype, the “external chain strike” is found in association with centered or uncentered broadstrikes.  In an external chain strike, the expanding edge of the broadstrike makes contact with the unstruck portion of an off-center coin protruding from an adjacent striking chamber.  The circular outline of the broadstrike is interrupted by a flat segment.

Chain strikes are sometimes mistaken for straight and curved clips.  Several diagnostics serve to distinguish the two errors:

1. A chain strike shows a distinct contact facet while a clip doesn’t.
2. Design elements bordering a chain strike show no metal flow.  Design elements bordering a clip will show metal flow.
3. A coin with a chain strike will weigh the same as a normal coin.  A coin with a clip will be underweight

Above, at left, is a conventional chain strike with a straight edge.  At right is an off-center cent with a concave chain strike located along the lower left portion of the struck tongue of metal.

The off-center 1999 cent seen above (left) shows a sinuous (sigmoidal) chain strike.  The 1999 cent shown above right is a centered broadstrike with an external chain strike at the 1:00 position.