AT vs NT??? 1881s morgan $

I first started hearing the term from dealers and on the forums about 20 years back. Maybe not so long on the forums. Your thinking on density is probably correct. Some use the term, work hardened. I'm thinking the term draft toning was before my time. Not sure. It has been duplicated.

 

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For morgan toner lovers who haven't seen this site... read up, then read again and then one more time.

This is where I first learned about pullaway and elevated chromatics...

http://www.jhonecash.com/coins/tonedmorgans.asp

 

Newbie asking another question, "meltdown shop"? What and where are these, I'd like to find a few like this.

 

A "we buy gold" place maybe

 

Ah, we call them Pawn Shop here and these scum bags try to get top dollar from culls. It's a joke.

 

That's exactly the proper term as used by Mint personnel and professional numismatists...forever. I forgot all about it Thanks!

 

Have you actually seen it done?

 

IMO, here is one of the problems a TPGS MUST face on a minute to minute basis:

0933: Genuine toned $ w/"Draft" toning.
0934: Genuine toned $? "Draft" toning looks OK but subdued...that coupled with
the irregular ABSOLUTEY, ARTIFICIAL LOOKING toning (?) on the rest of the coin...

Now the TPGS must "make the call."

I'm not 100% sure on this coin. It's very pretty BUT the ONLY thing that makes me unsure either way is the presence of the "Draft" next to A FEW of the stars. Rest of the coin is thumbs down. What would you say as a grader? NO Full photos available as photos were taken a long time ago.

 

I work for a metal cold roller. We buy material (Ti, SS, Ni, etc.) at 0.01" thick in coil form and we are capable of reducing it via 20 high Z mills to 0.000085" thick. In our world, work hardening occurs when you can no longer reduce the material and it becomes brittle. The danger with further reduction without a strip anneal is cracking, breaks etc.

It's interesting to see this same term used when discussing pull away toning. You can certainly understand the stress points directly adjacent to the devices/details on the coin. I can "see" how these areas would tone differently due to the slight differences in the material at a microscopic level.

 

I like, I like...Now a question.

I'm having an Email discussion about the stress marks on Spanish 8 Reals. Theory goes they were imparted into the strip as it was being "pulled" thinner before blanking.

Here are some photo's I just took (don't have time to dig out better ones): Also makes sense that the cracks should all be in the same basic direction. Have you seen this happen at the mill with brittle strip? Any thoughts? Thanks.

 

I have never heard it called draft toning. I have always heard it called pull-away toning. There have been several people say that convincing AT'd coins have been produced with pull-away, but I've never seen it myself (and, when asked, they have been reticent to show proof). If anyone has a picture to show, I'd love to see it.

In an extreme case of work hardening, the metal become very brittle, as you describe. However, any time the metal is stressed, there is a certain amount of work hardening. If you think of how the coin is produced, the metal of the planchet "flows" (for lack of a better term) into the die. The movement in the metal produces a certain amount of work hardening around the devices.

Work hardening is also a major concern in the production of dies (especially in the old double-squeeze system). The soft die steel was work hardened after the first impression of the hub, and then had to be annealed before the second impression. During the annealing process, the dies could warp. When the second impression occurred, all the details would be slightly off: this is the source of most hub doubling. Also, if the die was improperly annealed, it would wear quickly and you would get excessive die deterioration doubling.

 

I'll question that. Rest is good. Thanks.

We never gave it a name in the 70's. AT was not a problem back then as BU was the rage and many toned coins were dipped by EVERYONE. As I wrote before, "Draft" was used in the 1980's and IMO "pull-away" is a more descriptive and better term that I'll try to use from now on; but old habits facepalm: right @Kentucky) are hard to break.

 

Explain your question?

I don't know if "most" was the right choice of word, but "some," or "much" are definitely the right ones.

 

Let's just agree on some for now.

 

I've never heard it called drafting or the theory attached to it either figured I'd give you the benefit of the doubt though and see if others chimed in who have heard of it.

 

It's old timey stuff, long before the Internet, coin forums, etc.

Now I like "pull-away" much better.

 

Not exactly. Without going into too much detail, the work rolls are the only 2 of the 20 in the mill box that touch the material. The finish on the material is directly related to the "polish" on the rolls. The other 18 rolls all play a role in shaping the material, but they do not touch the metal. Any small imperfection on the work rolls will be imparted on the material. So the mill operator is responsible for monitoring the material (along with some automated visual monitoring) and reacting to imperfections. If he sees a problem, he stops the mill and pulls the rolls. Generally, we can reduce most material 70-80% before it work hardens. At that point, the "excess" material migrates to the edges. What we see is edge ripple and potentially small cracking. To further work the material, we need to slit the edges off and then anneal the material. If you try to work material with any edge cracks, you risk "breaking" the material in the next reduction.

Now, when you "pull" material, which in laymens terms is what is happening, you start to orient the grains in the material. The naturally orient in the rolling direction. Part of the annealing process tries to change the isotropy of the grains.

Anyway, when I see stress marks like in your photograph, I believe them to be planchet "errors". The planchets likely were not annealed properly, therefore, the material was a little brittle and the grain orientation was not minimized. The issue became magnified during the minting process.

 

Absolutely agree with the bolded sentence. I was trying to convey that in my message, but apparently, I didn't clarify it enough. I believe the pull away toning is impacted by this hardening as the highest stress point in the material is right around the "details" (stars, devices, date). Right at the junction of the fields and the devices/details.

I did not comment on the dies, but what you posted certainly makes sense. When I worked for a motor lam stamper, we had 150+ high speed presses using primarily progressive dies to produce the lams. At the time I worked there, we purchased the dies, but the company had a long history of die manufacturing as well. We used carbon inserts on dies in which 3 million + lams were needed. I believe die life with carbon inserts was 300 million or so lams. Of course, there was die sharpening etc... I'm only mildly familiar with the different grades of tool steel used when making the dies. I didn't really get into "science" behind the preparation of dies for production.

 

I like it as well because it is visually descriptive. I'm a visual learner, or so I've been told.

 

The "we buy gold" place near where I live is much better than the pawn shops in the area. The pawn shops are terrible and have absolutely no numismatic knowledge whatsoever.