choice 1957-D Unc Lincoln with cool oddity

[coppersleuth]

Take at look at this beauty! Any thoughts on what happened here?

The "N" of "IN" is on a raised chunk of metal. Pretty neat looking.

http://farm2.static.flickr.com/1416/549676884_9895fcae7f.jpg
http://farm2.static.flickr.com/1296/549677056_8339f33e82.jpg
http://farm2.static.flickr.com/1404/549677038_248beefd2b.jpg
http://farm2.static.flickr.com/1006/549677034_d4586df15d.jpg

[Danester]

It looks like the Obverse Die was "banged'" and "gouged" by some object after it was prepared for coining. Maybe by a tool used to tighten the die into the press.... or maybe just setting it down too roughly.

Danester

[Danester]

What is the Year and Mint of this Lincoln Cent?

[Danester]

OK.... I missed the 1957-D in the title.

It's a die variety !

[mikediamond]

Die damage. The striations would seem to indicate a very short, broad die gouge. As to what made it and when, who can say?

[wavysteps2003]

It is a neat die gouge as Mike pointed out. You can even see that it reached into the recess of the N and left some faint striation. There is one other point that may show the direction of how the gouge was made. If you look at the left leg of the N you will see that the inner edge has been planed a bit, forming a type of doubling. This may indicate that the direction was from right to left (mirror image for it is the die that was damaged).

BJ Neff

[Danester]

Here is a possiblity. If you held two dies (one in each hand) and banged the edge of one on to the face for the other.... then you might have a "ding" like we are looking at.

Danester.

[eagames]

That's about what I was thinking when I saw it, maybe they dropped one die on the other?

[coppercoins]

It's most likely a tooling mark left on the die. What it was caused by is something nobody can answer, but it was probably metal, like a screwdriver.

[Dick]

Gentlemen, I'm no metallurgist, but it is my impression that it will take more than "dropping a screwdriver, or somethng" on a die to damage it. I believe that the dies are VERY hard, as in "case-hardened", so that they will withstand the repeated blows from the srtiking of the planchets, in the minting process. It would be very difficult to damage anything in this fashion, from "dropping anything on the die, even another die". Admittedly, it would have its effect, [later], but that is due to the brittleness of the metal in the die itself, due to the hardening process, necessary to withstand the many thousands of repeated strikes needed to mint the coinage. Not well expressed, but I think you will understand what I am trying to say. Maybe someone will be able to clarify for me. Thanks,
Dick

[Earwig]

I dont know what made the mark but as far as steel goes the material used to make die has come a long way. Ill bet the pretreat rockwell in 57 was way lower and the material even after heat treat was way softer then some of the tool steels that they use now

Eric

[wavysteps2003]

Recently, a thread has come up concerning die hardness. This all had to do with the "extra leaves" on the Wisc. quarter and the theories of how they came to appear. While I am not going into the theories of how these leaves came about, there has been enough of that in COIN WORLD, with more to follow, I will comment on die hardness.

This mark had to be made with force and not something "dropped" (unless there was very much weight to it) onto the die. Just how much force? One of the threads from a leading expert in the field was his account of a punch, a 6 pound mallet and an old U.S. Mint die and his inability to even leave an appreciable mark on that die. Yes, they are that hard, somewhere in the range of 54 to 60 in the Rc (Rockwell) hardness (the larger the die, the more hardness they tend to have). Most tooling steel (used for tools and such) is in the neighborhood of 40 Rc so there is a big difference.

As to the cause of the die damage to this particular die, I would be hard pressed to take a guess. My thought is that it happened during a striking of the coin, however, there seems to be direction in the horizontal plane which complicates this contemplation.

In any case, the damage is unusual and the coin should be kept as a collectible piece.

BJ Neff

PS - On reading Eric's response, he is correct. For some reason, according to Chris Pilliod, the MINT was late in switching to premium steel alloys such as 52100 and L2 and waited until 1975 even though they were available long before that time.

[Earwig]

Ill bet they are using M2 or M4 for there dies now its the state of the art broach and die steel and even better then the T15 that steel companys are trying hard to push as the best. T15 is simialer but with tungsten added

Eric

[Dick]

Eric, you take me back to the "good old days", when I worked for ASARCO, in Tucson,AZ, (actually Sahuarita). In the mining, and refining industry, they use certain alloys to withstand the constant wear on the lining on the mills, Rod, and ball. They were using NI-CHRO-MAG in the lining, and it is HARD! It is very heavy, as well. But it still gets "sanded" down pretty dast with the slurry going over it. The M2, and M4 you mention, indicates a Magnesium alloy. HAve a nice day!
Dick

[Earwig]

Dick im glad to bring back good memories. Since becoming disabled i help do invoicing and colleting at a friends machine shop and ive learn alot about dif alloy steel havin to order materials. And with the prices of steel alloy steel goin through the roof im surprise we arnt getting pot mettel coin yet. Judging by the mints financial reports they are gunna have to do something or we all need to hoard coins so the gvernment has to order lots more. You know they are 1 of 2 government entities that are self funded and are run like a buisness. But im sure if they show a loss they get bailed out somehow.

Eric