I'm having trouble visualizing die bulges. Does someone have a good picture?

Longacre

I was reading the Winter book on New Orleans gold. For several issues, he mentions that particular coins have die bulges in certain places. For some reason, I just cannot visualize this attribute. Does anyone have a good picture of a die bulge, or is it something that is difficult to photograph?

numisma

Not the best example, but one that I have handy. Some early halves and early coppers have dramatic die bulges. The quarter below shows a die bulge (or swelling) at the lower right on the reverse.

coinguy1

From a Heritage sale: "1C Head of 1794 VF30 PCGS. S-22, R.1. The "Mounds" reverse and easily identifiable as such by the die bulge at the top of the wreath........"



Another:

"1807 1C Large Fraction MS62 Brown PCGS. S-276, R.1. BDS IV, the mint-made die bulge at the lowest left curl is prominent....."

Longacre

Thanks. These are great pictures!

numisma

Another one from Heritage. This one from the Reiver sale in January.



Heritage's description:

1800 1C S-200, B-15, R.3--Corroded--NCS. Fine Details. VG7 EAC. An early die state with a reverse bulge at ST, but no other apparent die defects. Both sides have light corrosion, evenly distributed across the entire surface, with olive and tan coloration. A couple tiny rim bumps are only visible with close examination. The reverse die gradually broke down during the production of several thousand coins, as seen in the next lot.

PerryHall

Can someone provide a written definition? Is a die bulge the opposite of a sunken die (die surface becomes depressed after many repeated strikes)? What causes a die bulge?

numisma

<< <i>Can someone provide a written definition? Is a die bulge the opposite of a sunken die (die surface becomes depressed after many repeated strikes)? What causes a die bulge? >>



A die bulge (or die swelling) is caused by a sunken die. Die bulges are most prevalent on early U.S. coins due to the simple limitations of 1) the die material and, 2) the manufacturing process of creating working dies. Some dies that were improperly manufactured would begin to sink or cave in localized areas. A coin struck from a sunken die would show a raised mound or hump in the area of the die sink. As a result details will be lost since there's not enough material in the planchet to fill the void created by the sink. Eventually a sunken die would deteriorate by developing die cracks and cuds. You may sometimes see a terminal die state which renders the die useless and beyond repair.

Advanced collectors of early coins like to study and collect die states. Some coins could have 10-15 die states, or even more, that are collectible. This is especially true of early Half Cents. Ron Manley wrote a book dedicated to the subject of die states on early U.S. Half Cents. Great book. By following the die states via pictures and descriptions, you get an almost animated picture of the life of that particular die marriage. Sometimes you will even see where a die was repaired to try to extend its life, only to see it completely fail a short time later.

CaptHenway

What he said.
A more appropriate term would be "die caused bulge," since the die itself is not bulged, but nobody uses that.
TD

PerryHall

Thanks for the detailed definition. I was familiar with sunken dies but the term die bulge was confusing. I think of a bulged surface (raised) as being opposite of a sunken surface (lowered). My understanding of the problem is that when the die steel was being hardened, sometimes there was an area of steel that was softer that the rest of the die and this area would compress or sink after many cycles of striking planchets under many tons of pressure.

RWB

Excellent reply, numisma!

As is occasionally the case, the common terminology is wrong. It should be "die depression" or "sunken die" or "collapsed die," not a "die bulge."

FYI- this was a common problem with Morgan dollar dies at San Francisco and was a problem during experiments with the 1907 Saint-Gaudens $20 VHR & HR designs. The die face and shank had to be correctly hardened or the die would sink during use.

Leiana

Great thread!

I learned something new today.

Thanks!

-Amanda

mgoodm3

So die bulge is a misnomer. should be a coin bulge.

ziggy29

<< <i>So die bulge is a misnomer. should be a coin bulge. >>

Or that it's a die *sink* and that results in a corresponding *bulge* on the coin.