Definition

• Cast Blank.  A cut metal disc processed and made to shape by casting rather than blanking. Cast blanks will exhibit some porosity, even when struck by dies and are an unsatisfactory substitute for blanks made from rolled stock. However, cast blanks were sometimes used in the past when a sufficient quantity of blanks from rolled stock could not be obtained, as with the establishment of a new mint. Cast blanks are used by necessity until a supply of rolled blanks can be purchased or the mint obtains its own blanking equipment and a steady supply of metal.
  Cast blank characteristics.  Cast blanks have rounded edges in addition to spotty surface porosity (tiny blow holes). Diagnostic detail of cast blanks being used for striking would include: a slightly lower weight in comparison with a piece of similar size and composition from rolled stock, striations like any other struck piece, and  striking may force the surrounding medal into the open areas of porosity somewhat obscuring them. (High magnification might even reveal where metal flowed into the open porous areas.)  Also,such cast blank pieces may, but not always, exhibit small surface bulges.
  Ancient cast blanks.  Most all ancient coins were made from cast blanks. The first coins were diestruck, but the metal used to strike these were first melted then poured into molds containing the proper amount for each coin. These globs or pellets were then placed between the dies, sometimes while the metal was still hot. Ancient coins infrequently exhibit cracks around the edge, technically called hot shortness, as a result of hot striking. When blanks are struck cold there is less likelihood of this metal anomaly.
  Greek and Roman coins were mostly make by these techniques, illustrated in most mint technology books (see Cooper, Becker). When the technology changed to hammered coinage, metal plates were beaten to the required thinness then trimmed to approximate circles with shears. Thus cast blanks were not used in the middle ages.
  With the introduction of the screw press came the need for better blanks. Rolling mills, screw presses and blanking presses were all developed about the same time (mid 1500s). Rolled strip stock was first blanked at the Paris mint in 1551 by Brulier. However, active mints could never keep up with the demand for these blanks.
  Early American cast blanks.  In the Western Hemisphere, no blanking equipment was available until early 1800s. Mints in Mexico and South America used primitive equipment to make blanks and struck irregularly-shaped cob coins. U.S. colonial coins were often struck in England on cast blanks. Walter Breen states the 1722 Wood's Rosa Americana coinages [Breen 83-142] were sometimes struck on cast blanks, as well as all the 1766 Pitt Tokens by James Smither [Breen 248-254] and other early American copper coins struck in the colonies.
  Cast blanks are not to be confused with cast coinage where the final piece is cast entire, not just the blank. Unfortunately, however, cast blank coinage leads to easy counterfeiting just as cast coinages do. Modern mints know better than to use cast blanks for coining and no modern coins have been so made for over two centuries.  See blanking. 
  References:                                                                                                                                   
  C58  {1969} Becker.
  C66  {1988} Cooper pp 10-12, illus.
  NC10 {1988} Breen.
  NE41 {1982} Doty (cast coinage).

  excerpted with permission from

  An Encyclopedia of Coin and Medal Technology

  For Artists, Makers, Collectors and Curators

  COMPILED AND WRITTEN BY D. WAYNE JOHNSON

  Roger W. Burdette, Editor

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