COMMENTS ON FLOWLINES

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V29 2026 INDEX E-SYLUM ARCHIVE

The E-Sylum: Volume 29, Number 45, 2026, Article 13

E-Sylum Feature Writer and American Numismatic Biographies author Pete Smith submitted this article in response to last week's "Surface Displacement" vocabulary term. Thank you. -Editor

The November 1 issue of The E-Sylum had an item on "Vocabulary Term: Surface Displacement" from Dick Johnson's Encyclopedia of Coin and Medal Terminology. It included this description of surface displacement.

"The movement of surface metal mass toward and into die cavities during striking. Generally surface metal flows from the outermost rim inward toward the center of the struck surface to fill the greatest cavity. Sometimes, but not always, striations will form on the surface; these are called flow marks and are always inward from the rim toward the center point like the spokes of a wheel."

This is contrary to what I have learned and what I believe. The unstruck blank is smaller than the collar in the die. Striking forces metal to flow outward to fill the collar. The fields in the die are the high areas with the devices as low areas. Pressure on the fields forces metal inward to fill the central devices. This does not create flowlines in the central device. In the outer areas of the coin, metal flows outwards to fill the lettering or stars and in late stages, may leave flowlines.

I have studied flowlines on the Classic Cents of 1808-1814 more than any other series. On December 2, 1984, I made a presentation at the Coinage of the Americas Conference at the American Numismatic Society. My presentation was "United States Turban cents, 1808-1814" published in the conference proceedings as America's Copper Coinage 1783-1857. Thus, I am citing as my authority something I wrote forty-two years ago. This is what I wrote for the 1984 COAC Proceedings and appears on page 154.

FLOWLINING

In the striking process the metal of the planchet is compressed between the two dies. It is also forced outward from the center. This lateral movement nay have a cumulative effect upon the dies. The effect can be observed as radial lines across the surface of the coin. Some of these radial lines are a natural product of the metal stretching. However, when they appear in the same place and pattern on many coins, it is apparent that the lines are transferred from the surface of the die. These lines can be observed at the points of greatest resistance. Often the points of the stars on the obverse or the letters of the reverse legend become connected to the rims because of this effect.

INCOMPLETE BOTTOMS OF LETTERS

Often the pressure of the dies and flow of the metal were not adequate to fill all the details near the outer edge of the dies. On the obverse the stars often lack the central detail. On the reverses, the letters of the legend may not fill completely. This effect creates a style of letter that may appear to come from different letter punches. However, this is a striking variation rather than a die variety.

The first image shows an enlarged area on the obverse of an 1812 Cent. Flowlines extend from the tops of the stars to the rim. There are shorter lines from the tops of some stars. The shape of the stars concentrated metal flow in these areas. It should be obvious that the metal flowed outward.

The second image shows an enlarged area on the reverse of an 1814 Cent. There is a void at the base of most letters. The metal flowed into the letters from the interior but there was inadequate metal to fill the base of these letters. There are also flowlines from the top of the first ‘A' to the rim.

The photo also shows that the flowlines are in the area between the wreath and the rim with no flowline in the central area of the coin.

Thanks, Pete. I agree, and I'm sorry I didn't catch that when preparing last week's issue. Metal flows outward, not toward the center. -Editor