2011 05 30

An
off-center cent with a “sideneck strike.” Driven toward the northeast by the
expanding die-struck portion of the coin, the unstruck edge collided with the
side of the adjacent hammer die neck.

Images by Mike Diamond.

As
a coin is struck, its expansion is abruptly halted by the surrounding collar.

When
the collar fails to deploy, a coin expands in all directions. As a result, all
off-center strikes and broadstrikes are wider than a normal coin, to varying
degrees.

On
some occasions a coin’s expansion is impeded, and the edge damaged, by machine
parts positioned above the collar plate.

The
most familiar obstacle to unfettered expansion is the neck of an adjacent
hammer die. In a dual or quad Bliss press (the last of which was retired in
2005), the close proximity of adjacent die pairs results in the occasional
production of a “sideneck strike,” also referred to as an “almost saddle
strike” or a “one-die saddle strike.”

A
typical example is shown here in an off-center Lincoln cent. At the pole
opposite the 1 o’clock position of the obverse face, we see a deep, concave
notch and an associated pressure ridge. The planchet represented by this coin
lay partly within one striking chamber and almost managed to encroach on the
adjacent striking chamber. In other words, the coin fell just short of becoming
a “saddle strike.” When struck, the expanding die-struck area pushed the
unstruck portion toward the adjacent striking chamber. It collided with the
side of the hammer (obverse) die neck as the latter was striking its own coin.

Sideneck
strikes are always concave and always closest to the adjacent striking chamber.
In most years, this chamber would lie along a line drawn from the 1 o’clock
position in Lincoln cents, or the 11 o’clock position in Jefferson 5-cent coins
and Roosevelt dimes.

Strike-related
edge damage of another kind is seen in an undated Jefferson 5-cent coin. The
pole opposite the off-center strike has a flat, vertically oriented contact
facet. It appears that the facet was produced when the unstruck portion of the
planchet was pushed south by the expanding die-struck area and collided with a
machine part. Another possibility is that the coin was hit while momentarily
immobilized by the two dies.

In
either case, we can’t be sure what machine part was responsible, although I
suspect a feeder finger. I’ve encountered these flat facets on quite a few
off-center and double-struck cents and 5-cent coins. In each case, the strike
is about 70 percent off-center and the contact facet lies opposite the base of
the bust.

The
introduction of the Schuler press introduced new types of strike-related edge
damage. This press uses a single die pair, with the reverse die operating as
the hammer die. The damage is primarily associated with multi-struck coins. A
representative example is provided by a quadruple-struck 5-cent coin. The first
strike was normal. The other strikes were delivered about 20 percent off-center
and are closely spaced. Edge damage is present on both the right and left
sides. The contact facet on the right side is convex, slightly beveled, and
extends from 12 o’clock to 2:30.

The
dies evidently struck whatever machine part rested against the coin. On the
left side the coin buckled when it collided with a hard object. The contact
facet here is quite compact and lies next to the w of we. It’s possible that
the coin was pushed laterally into an obstruction by expansion produced by the
off-center strikes. It’s also possible that an object hit the coin as the
latter was temporarily immobilized between the dies.

This
type of edge damage can be found on numerous multi-struck cents, 5-cent coins,
and Washington quarter dollars struck by Schuler presses. The pattern is
consistent, although the long facet and the short facet can be located on
either the right or the left side.

The
affected coins all show a sequence of strikes involving a normal (or at least
centered) first strike, and one or more closely spaced off-center strikes.
Coins in which the off-center strikes are widely spaced or erratically
positioned typically do not show this edge damage. The long facet that hugs the
edge of the off-center strikes is almost certainly caused by contact with a
feeder finger. I’m not sure about the short facet.

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http://www.coinworld.com/articles/machine-parts-above-collar-can-impede-expandi/

Copyright
2012 by Amos Hobby Publishing Inc. Reposted by permission from the March 22,
2012, issue of Coin World.)