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This is the first of three varieties of experimental alloy pieces made by the International Nickel Company as a replacement for silver. They were one of several companies the U.S. Mint commissioned to find a suitable alloy replacement for silver. The others are P5340 and P5380.
The reverse has a space where a number defining the alloy used was etched with a carbide tipped vibrotool or entered in pencil in most cases as shown below courtesy of Bowers and Merena.
The listing below greatly expands Pollock which only entered those items in the Smithsonian. This listing also includes examples which appeared in the Bowers and Merena May 1994 sale.
Photo courtesy of Bowers and Merena.
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Pollock #
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Composition
|
Test #
|
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P5195
|
german silver (same as P5280)
|
none
|
|
P5200
|
copper 75%, nickel 25%, copper core (same as P5270)
|
none
|
|
P5205
|
copper 40%, nickel 60%
|
none
|
|
P5206
|
copper 55%, nickel 45%
|
none
|
|
P5208
|
copper 75%, nickel 25%
|
none
|
|
P5210
|
titanium
|
none
|
|
P5212
|
aluminum
|
none
|
|
P5215
|
silver 90%, copper 10%
|
10
|
|
P5215A
|
silver 87.5%, copper 12.5%
|
2
|
|
P5215B
|
silver 85%, copper 15%
|
3
|
|
P5215C
|
silver 80%, copper 20%
|
4
|
|
P5215D
|
silver 72%, copper 28%
|
5
|
|
P5215E
|
silver 60%, copper 40%
|
6
|
|
P5215F
|
silver 50%, copper 50%
|
7
|
|
P5215G
|
silver 30%, copper 70%
|
8
|
|
P5220
|
silver
|
11
|
|
P5225
|
nickel
|
12
|
|
P5230
|
nickel 95%, silicon 5%
|
13
|
|
P5235
|
nickel 95%, silicon 5% on permalloy core
|
14
|
|
P5240
|
nickel 87%, chromium 13%
|
15
|
|
P5245
|
nickel 86%, chromium 14%
|
16
|
|
P5250
|
nickel 80%, chromium 20%
|
17
|
|
P5255
|
copper 70%, nickel 30%
|
18
|
|
P5260
|
copper 75%, nickel 25% on permalloy core
|
19
|
|
P5265
|
Incoloy alloy 800
|
20
|
|
P5270
|
copper cored copper-nickel (same as P5200)
|
21
|
|
P5275
|
stainless steel (310)
|
22
|
|
P5280
|
copper 66%, nickel 17%, zinc
17% (same as P5195)
|
23
|
|
P5285
|
copper
|
24
|
|
P5290
|
aluminum alloy (7075)
|
25
|
|
P5295
|
Iron Base (1010 steel)
|
26
|
|
P5300
|
zinc
|
27
|
|
P5305
|
copper 99%, nickel 1%
|
2-7
|
|
P5310
|
magnesium
|
28
|
|
P5315
|
niobium (columbium)
|
29
|
|
P5320
|
stainless steel (430)
|
30
|
|
P5325
|
titanium 90%, aluminum 6%, vanadium 4%
|
31
|
|
P5330
|
brass 30%, zinc 70%
|
32
|
|
P5331
|
silver 50%, copper 40%,
nickel 5%, zinc 5%
|
33
|
Image courtesy of StacksBowers.
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