50c 1795 / 1795 3 leaves - another die break

lilolme

Sorry got another die break.
50c 1795 / 1795 recut date 3 leaves (O-111)
This one is on the reverse and about half way across from dentil to lower middle of eagle breast. It appear that the crack stops/starts at the dentil and does not extend to the outer edge.

HA auctioned an AU58 Nov 2015 and had this in the description:
The reverse has the usual distinctive die crack across the eagle's left wing and body, with a co-planar reverse die face. Note that the eagle's details below the crack are much sharper than those above the crack.
https://coins.ha.com/itm/early-half-dollars/1795-1795-50c-recut-date-three-leaves-au58-ngc-o-111-high-r4/a/1190-33414.s?hdnJumpToLot=1&x=0&y=0

Stacks auction VF30 Aug 2011 has a similar description:
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.

This appears similar to the previous $1 1798 as far as a shift in height from one side of crack to another. I still can't visualize how this happens if the die is not broken and solid below the die crack. Hmm....(some residual stress in the die material?)
And again the strike appears weaker on one side versus the other....

It does give the half dollar a distinctive look in mid to lower circulated grades as the top of the wing and eagle are worn flat and below appears with all feathers showing.

pcgs XF45

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pcgs VF25

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pcgs VF25

jayPem

Recut date, that ones on my bucket list.
😘

yosclimber

I still can't visualize how this happens if the die is not broken and solid below the die crack.

Below the crack, the die is solid.
Above the crack, the die is not solid. It gives way when the strike happens, so it is not able to provide enough
pressure there to move the planchet metal deep into the die.

LanceNewmanOCC

to add to yos's accurate descript, pieces of the die could also be missing. sometimes they come off in thin, uneven layers and multiple pieces (die progressions are neat!), which is why we get such odd looks around retained cuds.

i LOVE that toned vf25. yowza

lilolme

@yosclimber
Thanks. I thought about something like that but I had two other thoughts.
Why does it happen on one side.
Why is one side higher than the other - I think this is correct because they note a step or shelf. It appears the top side of the crack is higher than the lower side and therefore it gets more wear.

Also on the 1798 it had a similar step that showed up on a vertical wear pattern as if one side is higher than the other even in the fields on this one that was top to bottom. So I start thinking the surface of the die is lower/higher but I can't visualize this. So it may be something to what you note and has to do with the strike pressure also.
Thanks again.

lilolme

So I just noticed that LA sold one in Sept 2021. Missed that one with the initial search (HA and Stacks). Not sure if this is correct but this is in the description.

https://legendauctions.hibid.com/lot/97054916/50c-1795-1795-recut-date--3-leaves--pcgs-f15/

A dramatic die break on the reverse explains the scarcity of this marriage, as the break traverses the reverse and caused this die to fail. The crack created two different planes on the surface of the die, resulting in sharper definition below it than above it.

Did the die fail?

I can't post the HA AU58 but it kind of shows the step and a weaker strike on top.

yosclimber

[1848-O V-1A, retained cud above ED, Crain #1355, from Newman Numismatic Portal]
It is the same effect you see when there is a retained cud.

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.

lilolme

@yosclimber
That is a good way to try to visualize it. I am thinking it has to do with the strike pressure on the heavily cracked die and as in your example one side get 'pushed' down for some reason??? Maybe the heavily cracked die is slightly off side to side and this starts it???

Thanks making a little sense now (I think). Don't know why I keep thinking about it because die stuff has never been my focus.

Either way a cool looking half in the worn conditions.

Had a previous retained cud and @Nysoto gave good info.
https://forums.collectors.com/discussion/1074571/1797-raised-date

Nysoto

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:

ricko

Thanks for the interesting and detailed explanation of this anomaly.... cleared up some questions I had. Cheers, RickO

Nysoto

"Quench cracking: During quenching, the transformational and residual stresses developed during quenching of steels can cause cracking during heat treatment."
"Elevated temperature failures tend to follow the grain boundaries and are referred to as "intergranular (between the grains) failures."

Grain boundaries in metal:

LanceNewmanOCC

@Nysoto said:
"Quench cracking: During quenching, the transformational and residual stresses developed during quenching of steels can cause cracking during heat treatment."
"Elevated temperature failures tend to follow the grain boundaries and are referred to as "intergranular (between the grains) failures."

Grain boundaries in metal:

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LOVE IT !

that is pretty close to how i visualized it; during the essentially 3 steps. initial melting to make the die (imperfections can happen), during tempering and/or other process (imperfections can happen) and during the extended life and further actions to help the dies (imperfections can happen).

when one starts breaking it all down, makes ya wonder how some of the dies lasted as long as they did given how many extra strikes past estimated die life they went, how many times they clashed, were tilted and struck each other, etc etc.