By Steve Carr
Sometimes, two coins with the same date will be noticeably different. One coin may have smooth fields and strong detail while a second coin may have radial lines (called flow lines) in the fields and softer details. How can this be?
Die states are especially evident on early American large cents. Explanations in this blog will use large cents to explain the differences.
The whole purpose of the minting process is to move metal by using a hard metal device (a steel die) to impart an image to an object made of softer metal (a copper, silver, or gold planchet before striking, a coin after). When the die and planchet are brought together, metal on the softer piece, a coin, is moved and forced into recesses in the harder die. This creates the raised devices, stars, numbers, and letters on the coin.
Heat and friction created during the striking process also moves metal on the die face, although at a much slower rate than on the struck coins. Thus, dies "wear." Some dies also crack, sometimes in many places. Die wear, and the development of cracks, does not happen all at once. It is a gradual process and can be seen if you look at a number of different coins of the same variety. Since die wear progression can be observed on coins, those struck from new dies are identified as EDS, or Early Die State. As the dies wear, coins are identified as MDS, Middle Die State, or LDS, Late Die State, where struck coins often show significant die wear and cracking.
Some dies cracked before they were even used. One example is the obverse die used to strike 1818 N10 large cents. Every known example of this variety has cracks through the stars on the obverse. These cracks probably formed when the die was hardened.
The hardening of the steel dies was probably the most variable factor in die life. Some dies cracked during the hardening process (like 1818 N-10). Others were improperly hardened, creating dies that were too soft or too hard, often only in certain spots. If too soft, a die would wear rapidly, as the steel in the die was easier to move. As the metal on the die moved, it created small ridges and valleys, radiating out from the center. This is called flow lining, and usually appears first near the rim. Flow lining occurs on almost all dies eventually.
A too soft die could suffer from rounded details and "crumbling," where small pieces of the die broke off, usually around the legend and devices. This is common on many 1849 cent reverses and is the cause of Liberty's "beard" on 1814 S295. A soft die might also exhibit sinking, where the surface of the die warps. This creates a bulged area on the coin surface. Good examples are the reverse of 1797 S138 and the obverse of 1835 N19.
A die that was too hard would tend to crack and break, forming cracks and cuds with use. As this die was used, these die defects got bigger or longer and other defects may have occurred, like other cracks.
Alignment of the dies during striking also affected die life. Normal die alignment has the die faces centered and in the same plane. If the dies were not centered, one side of the coin would be off center while the other would be centered. If the die faces are not parallel, one side of the obverse and/or the reverse would be strongly struck, while the other side would be weak. 1794 S65 is probably the best-known example of a variety struck from non-parallel dies with strong hair details but a weak LIBERTY. Many Classic Head cents were struck from non-centered dies, as are several varieties of 1853 cents. Dies misaligned either way put extra stress on the die edges and this extra stress often led to more frequent die wear,
Sometimes, the dies came together without a planchet between them. This created clash marks, where part of the design from one die is transferred to the other, on one or both dies. Clash marks are present on most varieties of early American coppers.
A die was sometimes lapped, where the surface of the die was ground or filed away to remove clash marks and flow lines. Lapping a die lowers the relief on the coin and makes stars, legend letters, and the date weaker and narrower. Often, die state is determined by when a die was lapped. An example of this is 1850 N 21, where the digits in the date are much weaker in the lapped LDS.
Other dies were stored improperly and rusted. Coins struck from these dies have small raised lumps on their surface. This is shown on 1798 S 157, where EDS, without lumps, coins were struck, the dies stored where they rusted, and LDS coins, with these lumps, then struck.
In some cases, die states are delineated even further. The first coins struck from a die are sometimes called VEDS (very early die state). The last coins struck are sometimes called VLDS (very late die state) or TDS (terminal die state).
Most modem references for early American coppers list even more die states, each separated by specific die deterioration. Walter Breen uses Roman numerals to designate die state. Bob Grellman uses small case letters, and Ron Manley uses numbers. The 1804 C6 half cent has the most identifiable die states for a single variety, at 19.
As a side note, some die states are worth more than others. Coins in VEDS and
VLDS almost always command a premium. EDS coins also often carry a premium, as do unusual die states. The rarity of some varieties is enhanced by die state collectors, who have multiple examples of these varieties, representing the various die states. 1817 N 16 and 1818 N 4 are prime examples. Both are scarce (R4), but their values are much higher than other R4's. Increased demand lowers the availability of the variety. Hence, the higher price.
Collecting by die state can be fascinating. Watch a crack get longer, see cuds develop, and notice the lessening detail. The next time you look at a coin, see if you can determine its approximate die state.