What's with the strike on high grade 1948-D cents?

[dabrin]

I've noticed over the years that most 1948-D cents in high grade seem to have this type of strike where the outer bit is severely distorted. In this coin's case you can barely make out that "8" due to being so distorted.

Also, this coin appears to have a pretty big die crack right across Lincoln's forehead (Frankenstein?). I've magnified it below. Any comments on this?

[kloccwork419]

That’s a very worn over used die. Late stage. Just die wear

[Petespockets55]

I totally agree with Jason. Old, overworked dies.

[dabrin]

I realize these are overworked (worn) dies, but what die wear physically makes them cause the outer edge distortion on the obverse?

[jmangham]

The outer edges of this die wore out quicker than the rest of the die. Think of the die as having a smooth tapered edge rather that the nice sharp edge it started with. The area around the edge of the die becomes stretched, causing the effect you see on the coin.

[kloccwork419]

The edge is the weakest point.

[Petespockets55]

From our glossary:
"Die Deterioration Doubling: A circumstance that occurs from die deterioration whereby the devices show a duplicate image on a coin. As metal must flow into the recessed areas of the die during the strike to form the devices on a coin, the edges and corners of the design elements on the die begin to wear. Eventually, this wear shows as a doubled image on the coins they strike. On Lincoln cents, the date and mint mark are often the first to show this doubling, since these devices are in the middle of a field with no other counter-relief to aid metal flow."

As I understand Die Deterioration doubling metal flowing into the devices will wear on the edges of the incuse areas of the die.

It might be incorrect, but an analogy I use is that Die Detreioration Doubling is comparable to the damage to a riverbank caused by the current in a river as it flows past the bank.

Maybe think of it as "die erosion" affecting the devices?