Die lapping question

abitofthisabitofthat

What are the tell-tale signs that die has been lapped?

I came across an interesting coin, that I believe had evidence of die clashing removed. The coin is high AU, so the luster is pretty much intact. The area where I believe the evidence of die clashing was removed has a muted, somewhat flat appearance, compared to the rest of the fields.

Can someone familiar with the minting process, circa 1857, comment on the process of lapping dies, and what other evidence may be found on the coins struck from them?

Barndog

not much time to answer in depth, but I will get it started:

look for missing or weakened design elements

Here is an example that shows missing/weak berries (ok, missing in this case!), weakened arrow shafts, weakened arrow feathers, weakened leaves, and weakened letters.

MrHalfDime

Barndog chose an excellent example of a severely lapped die (one of the best from the Capped Bust half dime series) to demonstrate what to look for in a die that has been subjected to such treatment. The lapping process is an abrasive process, wherein any of several different processes, compounds, or tools may be used to remove damage from the surface of a working die. These include abrasive rubbing compounds for light treatment, all the way up to more aggressive treatments such as files or even grinding. The intent is to remove the upper layers of die steel from the surface of the die, lowering the relief of the die to a point where the damage (e.g., clashing, incorrect letter or numeral, or incorrect position of a letter or numeral) is no longer visible. Typically, these efforts are marginally successful, at best.

One key element to identifying evidence of die lapping lines on the coins they struck is to recognize that the lapping lines would be incuse, or below the surface of the die, making them in relief, or above the surface of the struck coin. This can best be seen using a stereo microscope or other binocular device; it is almost impossible to determine whether an anomaly is in relief or incuse from a two dimensional image. Lapping lines on a struck coin can appear very much like hairlines, except that the lapping lines will be in relief, whereas hairlines will be incuse in the coin surface.

JRocco

Nice coin Barndog and description MHD
Here is an example in the CBH series.
1832 O-120a. The lapping has removed all the birds tail feathers.

mozin

Here is the 1813 Single Leaf O-109a Bust Half Dollar in P50 with the CAC sticker. This marriage is R3, but the LDS here is R5.

LanceNewmanOCC

<< <i>Nice coin Barndog and description MHD >>



i concur.
.

harveypb

Here's another example of a lapped die on an 1836 O.116A 50/00 bust half.
Notice the olive leaves and stems are disconnected from the branches...