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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.
|
Pollock #
|
Burdette #
|
Composition
|
Test #
|
|
P5195
|
RB1125
|
german silver (same as P5280)
|
none
|
|
P5200
|
RB1410
|
copper
75%, nickel 25%, copper core (same as P5270)
|
none
|
|
P5205
|
RB1150
|
copper
40%, nickel 60%
|
none
|
|
P5206
|
RB1130
|
copper 55%, nickel 45%
|
none
|
|
P5208
|
RB1110
|
copper
75%, nickel 25%
|
none
|
|
P5210
|
RB1030
|
titanium
|
none
|
|
P5212
|
RB1000
|
aluminum
|
none
|
|
P5215
|
RB1160
|
silver
90%, copper 10%
|
10
|
|
P5215A
|
RB1165
|
silver
87.5%, copper 12.5%
|
2
|
|
P5215B
|
RB1170
|
silver
85%, copper 15%
|
3
|
|
P5215C
|
RB1175
|
silver
80%, copper 20%
|
4
|
|
P5215D
|
RB1180
|
silver
72%, copper 28%
|
5
|
|
P5215E
|
RB1185
|
silver 60%, copper 40%
|
6
|
|
P5215F
|
RB1190
|
silver
50%, copper 50%
|
7
|
|
P5215G
|
RB1195
|
silver
30%, copper 70%
|
8
|
|
P5220
|
RB1025
|
silver
|
11
|
|
P5225
|
RB1015
|
nickel
|
12
|
|
P5230
|
RB1135
|
nickel 95%, silicon 5%
|
13
|
|
P5235
|
RB1400
|
nickel
95%, silicon 5% on permalloy core
|
14
|
|
P5240
|
RB1140
|
nickel 87%, chromium 13%
|
15
|
|
P5245
|
RB1145
|
nickel 86%, chromium 14%
|
16
|
|
P5250
|
RB1150
|
nickel 80%, chromium 20%
|
17
|
|
P5255
|
RB1115
|
copper 70%, nickel 30%
|
18
|
|
P5260
|
RB1405
|
copper
75%, nickel 25% on permalloy core
|
19
|
|
P5265
|
RB1305
|
Incoloy alloy 800
|
20
|
|
P5270
|
RB1410
|
copper
cored copper-nickel (same as P5200)
|
21
|
|
P5275
|
RB1310
|
stainless
steel (310)
|
22
|
|
P5280
|
RB1125
|
copper 66%, nickel 17%, zinc 17% (same as
P5195)
|
23
|
|
P5285
|
RB1005
|
copper
|
24
|
|
P5290
|
RB1300
|
aluminum
alloy (7075)
|
25
|
|
P5295
|
RB1320
|
Iron
Base (1010 steel)
|
26
|
|
P5300
|
RB 1035
|
zinc
|
27
|
|
P5305
|
RB1100 - RB1105
|
copper 99%, nickel 1%
|
2-7
|
|
P5310
|
RB1010
|
magnesium
|
28
|
|
P5315
|
RB1020
|
niobium
(columbium)
|
29
|
|
P5320
|
RB1315
|
stainless
steel (430)
|
30
|
|
P5325
|
RB1205
|
titanium 90%, aluminum 6%, vanadium 4%
|
31
|
|
P5330
|
RB1120
|
copper
70%, zinc 30%
|
32
|
|
P5331
|
RB1200
|
silver 50%, copper 40%, nickel 5%, zinc 5%
|
33
|
|
|
