Question on Franklin Working Hubs & Working Dies

Intueor

After 1940, were modifications like abrading or polishing ever done on Working Hubs? I know these and other modifications like hand engraving were done on Working Dies. In doing research, I have come across the same modifications in several Working Dies. It would not seem practical to perpetuate the desired modification by reworking multiple dies. This would suggest the modification of a Working Hub. I have checked and the modified Working Dies all show the same Master Die markers as unmodified Working Dies. To illustrate, the image below shows a “Divot” that appears on the right (viewers) bell hanger yoke on the reverse of most circulated and Proof (sans Type 2) Franklins. This divot would be a “bump” in the Working Die. On a Working Hub, this divot would be a “hole”.

It makes sense that the Working Die would be abraded to remove the “bump”. However, therein lays the conundrum. This abraded divot appears in many specimens within the same year and Mints and spans several years. Yet it is not exclusive to any Mint or year as the majority of Franklin strikes have the divot. It is almost as if the Philadelphia Die Room periodically polished out the divot on Working Dies at random. This just seems too arbitrary for a working shop. However, if a Reverse Working Hub were modified to polish out the divot than it would make sense that the modification would perpetuate in Mints and years.

Any thoughts?

RogerB

An "Annual Master Hub" is the one from which all dated dies (obverse) for that calendar year are made. The same applies to the reverse except that it might be in use over several years.

As you imply, it is very likely that in any year there were several "Master Hubs" in use due to the number of working dies necessary to serve three mints and proofs. (See 1936-42 proof quarters for explanation.)

It appears that die records and all Engraver's notebooks from the 1940s forward have been lost.

Intueor

@RogerB and All
Your response to my question indicates that modifying Hubs/Dies can apparently occur at any step of the minting process. That was important to know.
I have more research to do and I will check your book again.
The new format for CoinFacts has put a limit on the detailed images needed for proper analysis.
Most of the other online resources do not have high-resolution images critical to tracking Hub & Die marriages.
Such a pity that all that wealth of material on internal Mint procedures was lost.

Thank you for your time.

illini420

Can't help with the answer to your question, but those are some very close up photos, took me a second to figure out what I was looking at, nice!

Intueor

@illini420 said:
Can't help with the answer to your question, but those are some very close up photos, took me a second to figure out what I was looking at, nice!

>
Thanks for the tip. Below is a wider shot to help avoid confusion. Your right, this is a tiny feature but examining Die markers the variations are sometimes minuscule.

Thanks

Ronyahski

You could not polish off a "divot" in a hub without lowering the surrounding area, something they would not want to do.

Intueor

@Ronyahski said:
You could not polish off a "divot" in a hub without lowering the surrounding area, something they would not want to do.

Thanks for the response.

Yes, that seems to be true. An abraded area into the surface of the Working Hub would be a raised area on a Working Die and an incused dimple on a coin. The image of the no divot specimen above does not reflect an incused dimple. But here is my problem. Examples of this polished no divot exist on Franklin reverse specimens from 1950 to 1963. If it were just Working Die polishing that would be an arbitrary modification to random working dies. Are there other possible explanations?

Hemispherical

@Intueor I have to say that you have some awesome micro pics!

RogerB

The very sparse Engraver's records from the 1930s-40s indicate that changes were not made to hubs that were in use. The Engraver would make changes on a copy hub and then prepare samples and possibly a test run to verify that the desired result was attained. A new hub was only put into use with approval of the Director and several other technical officers.

An annual master hub could, of course, be damaged during use and have to be replaced, or damaged and the fault undetected.

Intueor

@Hemispherical said:
I have to say that you have some awesome micro pics!

Thanks. iPhone 7 through a Stereoscope eyepiece. Hey, it works for me.

@RogerB said:
The Engraver would make changes on a copy hub and then prepare samples and possibly a test run to verify that the desired result was attained. A new hub was only put into use with approval of the Director and several other technical officers.

An annual master hub could, of course, be damaged during use and have to be replaced, or damaged and the fault undetected.

Thanks Roger,
Is it possible that by the 1950s, the above procedures changed?
It is not clear to me if you are talking about a Working Hub. At least during 1950's Franklin production, there must have been more than one reverse Working Hub. Specimens of 1950-51 Franklin reverses actually show at least three different Working Hubs. During this period 1949-51, there is also evidence the Reverse Master Die was re-engraved at least twice.

What is curious is that the scratches on the detail below are not raised or in relief (not an effect of lighting, I checked). If you look close, many of the lines are "valleys" or incused as you would expect to find if the abrading was on the Working Hub. Some of the scratches are raised but this would be a result of "displacement" during the brushing.

The images below give an indication of how the divot persisted through the series.