Adjustment Marks on Coins, why are they more common on the obverse?

BryceM

Forum member @edwardjulio asked a good question in another thread, but deleted it as he wasn't sure it was interesting enough. I thought it was worthy of discussion and thought-provoking. Here's his question:

• Adjustments marks on planchets, that I have seen on images of coins, seem to be primarily on the obverse. Was this a random event in the striking process or SOP at the mint?

I gave an answer in the other thread, but I'm interested to see what others think.

scubafuel

Here's my guess, but this could be completely off-base.
It seems likely that some (many?) early presses had the reverse die as hammer die. That's why almost all non-rim cuds appear on the reverse in early/bust coinage. Would the hammer die be more likely to obliterate adjustment marks than the bottom (obverse) die? That way the blanks could go in randomly, but most that fall with adjustment marks upwards would be erased.
Thoughts?

JBK

@scubafuel said:
non-rim cuds...
Thoughts?

My thought is that a cud involves the rim, and that a "non-rim cud" is a die chip or die break. But, I know there is some difference of opinion on the issue.

In regard to adjustment marks, I don't expect that the press operator would have taken the time to orient the planchet in any particular way, so I'll buy any explanation that suggests that the particular design is responsible for obliterating or not-obliterating any adjustment marks.

RogerB

The span of an obverse portrait causes less metal flow/deformation and the reverse eagle/field. Rate of occurrence was likely the same, but it's more evident on an obverse.

PerryHall

The number of adjustment marks on the obverse and the reverse is about the same. The difference is they are more noticeable or visible on the obverse since the design is normally plainer with more open space such as Liberty's cheek and fields while the reverse has a more busy or cluttered design with the eagle and many legends which tends to hide the adjustment marks. For the same reason Morgan dollars seem to have more bag marks on the obverse than the reverse when statistically the number would be about the same.

CaptHenway

@RogerB said:
The span of an obverse portrait causes less metal flow/deformation and the reverse eagle/field. Rate of occurrence was likely the same, but it's more evident on an obverse.

What he said. The same thing applies to drawing bench scrapes on the obverses of Morgan dollars.

Insider2

@scubafuel said:
Here's my guess, but this could be completely off-base.
It seems likely that some (many?) early presses had the reverse die as hammer die. That's why almost all non-rim cuds appear on the reverse in early/bust coinage. Would the hammer die be more likely to obliterate adjustment marks than the bottom (obverse) die? That way the blanks could go in randomly, but most that fall with adjustment marks upwards would be erased.
Thoughts?

I believe that most planchets that were adjusted show some signs of the adjustment after they were struck. Therefore, based on how few we see, I don't think a large number of planchets needed to be adjusted. If a coin shows no evidence of adjustment marks, they were either not on the planchet or they were of so little depth that they were struck out. I don't consider this to be a contradiction.

If I were a press operator, I would put the scratched side of the planchet in the orientation to the die (obv or rev) that woulds give the best chance of obliterating them when struck.

lkeigwin

@scubafuel said:
Here's my guess, but this could be completely off-base.
It seems likely that some (many?) early presses had the reverse die as hammer die. That's why almost all non-rim cuds appear on the reverse in early/bust coinage. Would the hammer die be more likely to obliterate adjustment marks than the bottom (obverse) die? That way the blanks could go in randomly, but most that fall with adjustment marks upwards would be erased.
Thoughts?

The hammer die was usually the obverse. But there were plenty of exceptions, well into in the early 20th century (Buffalo nickels and Mercury dimes, e.g.).

Adjustment marks are as common on the reverse as the obverse, in my experience.

I don't believe press operators had the luxury of time to examine each side of the planchet before inserting into the coining chamber. It was a speedy, if manual, operation.
Lance.

edwardjulio

@BryceM
Thank you for starting this new post with my question. The responses have been educational for me.