Skip to content

Broken Die

Broken Die.  A cracked or chipped die incapable of striking a perfect piece. Dies break in a variety of ways, and at different speeds. If the pressure is too great during setup

a die may break instantly – literally cleaving in two like two halves of a split log – or it may shatter  (shattered die) with a network of tiny fissures over the entire face of the die much like a shattered auto windshield. Or, the process may be very gradual: as with wear and metal stress in an area of the die causing the tiniest of fissure – a hairline diecrack – which, with continued use of the die, the crack appears to "grow," to lengthen and widen on successively struck pieces.

How diecracks grow.  Generally diecracks commence at the edge and progress

inward toward the center of the die's surface. Often these follow the paths of greatest stress, usually where there is steep-pitched relief – rapid rises and falls of relief. Legend

– the lettering nearest the rim – and the border elements are the greatest concentration of this precipitous relief that becomes the location of most stress.

Steep-pitched relief – in lettering, design and border elements – is where the

greatest amount of metal is displaced on the surface during striking. This is where the dies wear the most and continual striking causes metal stress to take its toll on the die, where most diecracks occur. Their growth is due to the continual pounding away in striking causing a small crack to lengthen, widen and deepen.

Pieces struck from the die during this deterioration exhibit the progression of the die cracking. A study of the stages of this process, with specimens of the different stages, is an interesting aspect of numismatics.

How diechips occur.  Two or more nearby diecracks may join together as they lengthen and deepen into the surface of the die. Ultimately they join in such a way that a small portion of the die may be completely surrounded by cracks and this portion is liberated from the mass of the die – in effect, it becomes a diechip.

While the diechip is still in position and before it falls out, it is called a retained chip.  As such it acts much like an insert in an insert die – it stays seated (particularly if the die is in the lower pile position in the press). The diecracks completely surround the chip; there are raised lines around the chip on all pieces struck from the die in that condition.

Once the chip falls out, this creates a die cavity, which – like any other die cavity – causes raised relief (lumps or bosses) on all pieces struck from that die. If a diechip is near the edge – between the legend and the rim or just a chip out of the rim edge – this is called a cud by collectors.

If considerable mass of metal fills the cavity and causes a large cud or boss, less metal is available to fill other areas of die cavities and the piece may appear weakly struck in these areas. Or metal may not flow outwards to form a perfect edge or particularly, the reeding. Often the piece is weakly struck at the point immediately opposite on the other side of the struck piece (metal flows toward the greatest die cavity and does not fill intended design cavities).

When a die breaks.  Normally a die is discarded when it breaks. In practice, it

seems, just a few more pieces are attempted to be struck before it is withdrawn, however.

When attempting to salvage a struck piece with diecracks or diebreaks chasing must be employed to remove the telltale lines.

To replace the die, its previous generation is sought – its hub, pattern or dieshell

– and a new striking die is made. In rare instances the original plaster models are brought back to use or new striking dies are made by edm from a piece struck by the die when it was in perfect state.

There have been instances when a hub is attempted to be drawn from a die if no predecessor exists. An example of this occurred in 1961 when New York numismatist Robert Bashlow attempted to reproduce the Confederate Cent from the original dies he owned. One die was broken, however; he took both dies to August Frank & Company of Philadelphia, who hardened the dies, bound the broken die securely, and drew hubs from both originals, in effect creating transfer dies. From these hubs new striking dies were made. The chances of this working every time are slim, but it met with success in this case.

See diechip, dies and diemaking, hubbing.

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.