Summary Early - Bust Die Issues (retained cud, split die / broken die)

lilolme

The below is information from previous threads but I thought I would try to consolidate and organize it to keep it together and possibly make it more readable. If you see something I messed up (or suggestion), then let me know.
@Nysoto @BillJones @yosclimber thanks for the input and let me know if you want something changed.
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***Retained Cud
10c 1797 16 stars

From https://forums.collectors.com/discussion/1074571/1797-raised-date#latest

@Nysoto provided
The reference guides don't show anything without at least a die crack on 1797 JR-1. The crack becomes a die break and then becomes a retained cud, but not a full cud. One theory from Chris Pilliod is the obverse die is the anvil die (on half dollars - but maybe also on dimes) and that is why there are no full cuds on early half dollar obverses, because the die chip cannot fall out of place being seated in the anvil position, whereas if the hammer die has a die break it can fall completely out which leaves a full cud as on early half dollar reverses:

@BillJones provided
I believe that this die was broken during the die preparation process. It probably broken when it was heated and dipped in water to cool it because of a defect in the steel. The die makers at the first mint were not that experienced and production errors like this were not unusual.

@Nysoto continued
In the words of Chief Engraver Robert Scot, in December of 1794:

"Namely, the precariousness and uncertainty of hardening and tempering the Dies, whereby they are often lost without striking a single Coin;"

Example - Retained Cud - Reverse order of die failure - 10c 1797 16 stars





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***Split Dies / Broken Dies (large die cracks)

From https://forums.collectors.com/discussion/1075255/50c-1795-1795-3-leaves-another-die-break#latest

Examples of Split Dies / Broken Dies
50c 1795 / 1795 recut date 3 leaves (O-111)


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Examples of the above at auction have had the descriptions:
The reverse has the usual distinctive die crack across the eagle's left wing and body, with a co-planar reverse die face.
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This unusual crack is bi-planar in nature, somewhat like a shelf, with the surface to one side of the crack lower than on the other side.

@Nysoto provided
The 1795/1795 three leaves always has the heavy die break, none are known without it, and no examples exist with a lighter crack. Probably the crack started during the hardening and tempering operations. I have posted this before and it is appropriate on this thread, from Chief Engraver Robert Scot's December 1794 engraving report to Congress:

"Namely, the precariousness and uncertainty of hardening and tempering the Dies, whereby they are often lost without striking a single coin;"

Scot is describing thermal shock from quenching the dies, where cracks can occur at the weakest area - along a grain boundary on the body centered cubic lattice structure of the die steel. Here is my example of this variety:

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As a possible way that the coin has a step or shelf at the crack as noted in auction descriptions
@yosclimber provided
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With a retained cud, a piece of the die is "loose" and gets pushed away from (lower than) the surface of the rest of the die
when the strike happens.
This makes that part of the coin higher.

Why does it occur on the upper part of the die crack in this case?
Probably because of the angle of the plane of the die crack below the surface of the die.
Think about the retained cud case. Probably the loose piece is fairly thin, so it moves down/outward during the strike,
along the plane of the die crack.
Here it is probably similar.
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From https://forums.collectors.com/discussion/1075169/1-1798-reverse-wear-pattern#latest

Example Split Dies / Broken Dies
$1 1798 4 Lines Knob 9 - B-5 BB-93

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@Nysoto provided
The error guys call these "split dies", I believe unlike an edge cud that could fall out, the split die break goes deep into the shaft of the die. This is the best example of a half dollar split die 1806 O-114a/T-16 (hair is either mine or my dog):

Edit - some error experts claim only lateral spread on a split die, and vertical displacement can be a retained cud. I think these could be a hybrid, they are obviously split with the die break extending well into the shaft, along with some vertical movement that shows up as two planes of different height on the coins.

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Additional Examples:

$1 1796 Sm Dt Lg Lt B-6 BB-64

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$1 1798 Pointed 9, Wide Date BB-110, B-16

ricko

Great thread, great pictures and educational/informative. Thank you for the consolidation. Cheers, RickO