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Category IV - Die Errors - Concentric Lathe Marks (Lines)

Lathe Lines
By Jason Cuvelier

Over the past several years there have been various reports by collectors of having found Lincoln cents with raised concentric lines (marks) on the obverse or reverse face of US coinage. First identified on 1996D Lincoln cents, what was frequently observed were soft concentric lines that became stronger toward the perimeter of the coin, yet did not go into the devices. On the reverses of various dated Lincoln cents, the lines are thinner, tend to be stronger in the middle and do go into the devices. While the the lone Jefferson nickel has thicker lines which resemble the appearance of the '96D lines yet go into the devices.

Ken Potter, of CONECA, has stated that he had a conversation with a Philadelphia Mint spokesmen about the occurrence of these coins (K. Potter CONECA website),”…[the Mint Spokesman] suspected that they probably had not polished the die blanks sufficiently to remove all the lathe lines.  The lines were created when the die blank was machined from a cylinder of steel according to him and we can presume that if this is accurate, that the hubbing process did not eliminate them completely.”

To clarify, dies are made from steel rods called Blanks, in the process of preparation the rods they are lathed into a conical shape of approximately 22°. Apparently, after reaching the desired shape, they are furthered polished to remove evidence of their formation. As hypothesized, the lines were inadequately removed from a number of different dies. After being hubbed, some of the lines remained. To the left is a drawing of a die-blank.

As there was no specific documentation of dies for coinage with Lathe Lines available, it was suggested that they be documented. Having acquired or borrowing several others from various collectors, a number of dies have thus been identified labeled with the Date, MM, denomination and listing number (e.g., 1996D #C LL 00#); if it ends with an "R", it is a reverse die; they are numbered 001 and onward by year as identified.

I am actively searching for new coins with Lathe Lines - see my SUBMISSIONS page for details on sending examples for inclusion to this site.

The LINKS below have photo collages and die markers for dies identified.