NATIONAL BUREAU OF STANDARDS REPORT

9917

Progress Report

on

CHEMICAL COMPOSITION OF DENTAL GOLD CASTING ALLOY

AND DENTAL WROUGHT GOLD WIRE ALLOYS

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
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NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT

311.05-11-3110560 June 30, 1968

NBS REPORT

9917

Progress Report

on

CHEMICAL COMPOSITION OF DENTAL GOLD CASTING ALLOY

AND DENTAL WROUGHT GOLD WIRE ALLOYS 12By

7 4

J. D. Eick, H. J. Caul, T. Hegdahl, and G. Dickson

1. Present address: Dept, of Dental Materials, School of

Dentistry, State University of New York, Buffalo, N. Y.l42l4

2. Research Associate, American Dental Association Research

Div., National Bureau of Standards, Washington, D.C. 20234

3. Present address: Institute of Odontology, Bergen, Norway.

4. Acting Chief, Dental Research Section, National Bureau of

Standards, Washington, D. C. 20234.

This investigation is part of the dental research program

conducted by the National Bureau of Standards, in cooperation with the Council on Dental Research of the American

Dental Association; the National Institute for Dental Research; the Army Dental Corps; the Aerospace Medical

Division, USAF School of Aerospace Medicine; and the

Veterans Administration.

NATIONAL BUREAU OF STAI

for use within the Government. B and review. For this reason, the | whole or in part, is not authorizi Bureau of Standards, Washington,

the Report has been specifically p

IMPORTANT NOTICE

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015

accounting documents intended

bjected to additional evaluation

sting of this Report, either in Office of the Director, National

the Government agency for which

ies for its own use.

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

- 1 -

Chemical Composition of Dental Gold Casting Alloy

and Dental Wrought Gold Wire alloys

J. D. Eick, H. J. Caul, T. Hegdahl, and G. Dickson

The chemical composition of 136 dental casting

gold alloys and 2l dental wrought gold wire alloys

was determined by an x-ray emission method. The

changes in composition from 1928 and 1932 to the

present time are small. There has been a decrease

in platinum content in both castings and wires.

About 1% nickel is found in the present-day wire

which was not present in 1928 and 1932.

Introduction

American Dental Association Specification No. 5 for

Dental Casting Gold Alloy and No. 7 for Dental Wrought Gold

Wire Alloy require that a minimum amount of gold and metals

of the platinum group be present in each type of alloy (l).

Therefore, a chemical analysis of at least the noble metal

content is necessary when these alloys are tested for compliance with these specifications. Compositions of dental

gold alloys were determined and published a number of years

ago (2, 3). Since modern formulations are not available in
—2 —

the literature, the total chemical composition was determined during recent surveys of these alloys. The chemical

compositions of 136 dental casting gold alloys and 21

dental wrought gold wire alloys were determined using a

modification of the x-ray emission method described previously by Eick, et al (4)

Methods and Materials

Two specimens of each alloy were cast into a flat disk

approximately 1 mm thick and 32 mm in diameter. The "lostwax casting technic" (5) was utilized with a gypsum bound

investment. An electric resistance-heating furnace connected

to a centrifugal casting machine, with a pyrometer attached

which measured temperature to within ± 15 °C, was employed to

melt and cast the alloys into molds preheated for two hours

at 650 °C. The specimens in the mold were quenched in water

immediately after casting, removed from the investment mold,

and mounted in acrylic resin to facilitate surface preparation and x-ray analysis.
-3-

The surface was prepared by finishing with 600 grit

wet silicon carbide paper. Each specimen was analyzed five

times in a multi-channel x-ray emission unit* using a sequence

designed to minimize the effects of instrumental drift (6)

.

The x-ray intensity data for each element were automatically

recorded on tape, then transferred to computer cards, and

corrected for absorption and enhancement effects before using the

the Lucas-Tooth and Price Equation (7)

.

The corrections

of silver and platinum intensities for an overlap resulting

from palladium and copperware necessary because less resolution was achieved with the PXQ. In the previous paper (4)

overlap was not a problem when the inverted sample three position spectrograph was used. The corrections were made as

follows

IAg ” mIPd “ IAg corrected

where m = 0.084

Ip t -mICu = Ip

t

corrected

where m = 0.0975

*The PXQ manufactured by Applied Research Laboratories.
-4-

The values for m were found to be very nearly constant

from run to run for the particular instrument that was

employed for the analyses. The corrected intensity values

for silver and platinum were then used in the computer program for the Lucas-Tooth and Price equation. This procedure

enabled the chemical composition of each element to be

determined to an accuracy of about 0.2% or less.

Results and Discussion

The chemical compositions of each casting gold alloy

and wrought gold wire are listed in Table 1. Each type of

casting gold and wrought gold wire alloy may be characterized

by representative formulas. The formulas for the casting

gold alloys are listed in Table 2. One class consists of

those alloys containing little or no platinum or palladium,

the second, those containing platinum but little or no

palladium, and third, those containing palladium but little

or no platinum. The last classification consists of alloys

containing both platinum and palladium..
-5-

The average compositions of the four types of casting

gold alloys are listed in Table 3. The gold content decreased while the copper and zinc content increased from

type I to type IV. The silver content was about the same

for types I, II, III, and IV, and both the platinum and

palladium content increased from type I to type IV. It is

well known that copper plays an important part in the hardening of gold alloys but these data suggest that palladium

and platinum may also play a significant role in the hardening mechanism of dental gold casting alloys.

The representative formulas for the type I wrought

gold wire alloys are listed in Table 4. These alloys

could be classified as those containing little or no nickel,

1% nickel, and 2% nickel. In general, as the nickel content

increased, copper increased, and platinum decreased. The

palladium and platinum content in these alloys is much higher

than in any of the casting gold alloys. The three formulas

for the type II wrought gold wire alloys are listed in

the same table. In general, these alloys contained more

nickel than the type I wires, while the palladium and platinum content was significantly less. The amount of other

constituents was comparable to those of the type I alloys.
- 6 -

The average compositions for the wrought gold wire

alloys are listed in Table 5. The type I alloys contained

less nickel, gold, silver and copper and significantly more

palladium and platinum than the type II alloys.

Table 6 compares the composition of casting golds and

wrought wires in 1928 and 1932 with those of 1968. The

modern casting gold contains less platinum and more gold

while the changes in the wrought gold wires are the presence

of about 1% nickel, an increase in copper content and a

decrease in platinum.

Summary and Conclusions

It was possible to represent each type of alloy by two

or three typical chemical compositions. The gold content of

the dental casting gold alloys decreased from type I to

type IV, whereas the copper and zinc content increased. The

silver content remained about the same for types I, II, III,

and IV. The platinum and palladium content generally increased,

with a large majority of the type IV alloys containing approximately 2% of both platinum and palladium. Many of the type I

wrought gold wire alloys contained little or no nickel and

large amounts of platinum and palladium. The type II alloys

generally contained approximately 2% nickel, little or no
-7-

palladium and platinum, and a larger amount of gold than the

type I wrought gold wire alloys.

The changes in composition for casting gold alloys and

wrought gold wires from 1928 and 1932 to the present time

are small. There has been a decrease in platinum content

in both wires and castings. About 1% nickel is found in

the present-day wire which was not present in 1928 and 1932.
- 8-

Bibliography

1. Guide to Dental Materials , American Dental Association,

Chicago, Illinois, 3rd ed. , 1966.

2. Coleman, R. L., Jr 0 Physical Properties of Dental Materials

(Gold Alloys and Accessory Materials) BS J. Res c 1, 867

(December 1928) RP. 32.

3„ Paffenbarger , G. C c ; Sweeney, W e T., and Isaacs, Aaron.

Wrought Gold Wire Alloys: Physical Properties and a

Specification. JADA 19:2061 December 1932 c

4. Eick, J. D .

Caul, H 0 J.; Smith, D. L. , and Rasberry, S« D.

Analysis of Gold and Platinum Group Alloys by X-Ray Emission

with Correction for Interelement Effects. App 0 Spect. 21,

324/ (1967) .

5 0 Skinner, E. W„ and Phillips, R. WQ The Science of Dental

Materials, Chapters 27 and 28. W. B„ Saunders Company,

Philadelphia, Pennsylvania, 6 th ed., 1967.

6 . Swindells, J. F. Calibration of Liquid and Glass Thermometers, NBS Monograph 90 10-11 (1959)

7. Lucas-Tooth, H. J. and Price, B. J. A Mathematical Method

for the Investigation of Inter-Element Effects in X—ray

Fluorescent Analyses, Metallurgia 64, 149 (1961) 0
1

2

3

4

56

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

TABLE 1

CHEMICAL COMPOSITION OF TYPE I - CASTING GOLD ALLOYS

Gold

%

Silver

%

Copper

%

Palladium

%

Platinum

%

Zinc

%

Total

%

80.2 11.8 4.6 2.8 0.0 0.0 99.4

80 o 2 11.8 4.6 2.8 o e o 0.0 99.4

80.6 llo 8 4.6 1.9 0.1 1.2 100.2

81.2 12.0 3.3 3.6 0.0 0.3 100.4

81.2 11 . 8. 4.4 1.9 0.4 1.0 100.7

81.2 10.2 6.0 0.9 0.0 0.2 99.5

82.5 10.6 6.2 0.0 0.1 0.0 99.4

82.8 10 o 6 6.0 0.0 0.0 0.0 99.4

82.8 11.2 4.6 lo 0 0.0 0.0 99.6

83.0 10.8 5.6 0.0 0.1 0.0 99.5

83.0 11.6 4.6 0.0 0.1 0.4 99.7

83.2 8.2 7.3 0.6 0.2 0.2 99.7

83.2 11.5 4.6 0.0 0.1 0.4 99.8

83 o 6 11.0 5.0 0.0 0.0 0.0 99.6

83.6 10.8 5.0 0.0 0.1 0.0 99.5

84 0 4 10.0 5.0 0.0 0.1 0.0 99.5

86.2 5.6 3.7 3.7 0.0 0.6 99.8

86.6 6 o 6 4.2 0.0 1.8 0.0 99.2

86 o 8 8.8 4.0 0.0 0.0 0.0 99.6

88.8 4.4 5.2 0.0 1.0 0.4 99.8

89.4 8.0 2.1 0.1 0.0 0.0 99.6

89.8 6.7 3.2 0.0 0.0 0.0 99.7

90.8 4.0 4.8 0.0 0.1 0.0 99.7

91.3 5.4 2.9 0.0 0.1 0.2 99.9

91 0 5 5.3 2.8 0.0 0.0 0.0 99.6

91.9 5.4 2.2 0.0 0.2 0.6 100 . 3 . 92.6 4.3 2.7 0.4 0.0 0.0 100.0

92.8 3.7 2.2 0.0 1.0 0.2 99.9

95.8 2.4 1.6 0.0 0.1 0.0 99.9
TABLE 1

( continued)

CHEMICAL COMPOSITION OF TYPE II - CASTING GOLD ALLOYS

Alloy Gold Silver Copper Palladium Platinum Zinc Total

No„ % % % % % % %

1 73.0 14.6 6.0 5.6 0.0 0.0 99.2

2 74 0 7 14.4 7.0 2.8 0.0 1.1 100.0

3 75.2 14.2 6.9 2.8 0.0 0.7 99.8

4 76.6 13.6 8.2 1.0 0.0 0.0 99.4

5 76.7 13.5 8.2 1.0 0.0 0.0 99.4

6 76.8 10.3 10.5 1.4 0.0 0.6 99.6

7 76.8 12.6 8.0 1.9 0.0 0.1 99.4

8 76 o 8 13.4 8.0 0.9 0.0 0.0 99.1

9 77.0 11.2 10.2 0.9 0.0 0.1 99.4

10 77.0 11.2 7.2 1.9 1.8 0.0 99.1

11 77.0 13.8 7.0 1.2 0.0 0.5 99.5

12 77.2 13.0 8.0 0.9 0.1 0.7 99.9

13 77.3 11.6 9.2 1.0 0.0 0.6 99.7

14 77.4 13.3 6.6 0.0 1.9 0.0 99.2

15 77.4 12.4 7.4 1.9 0.0 0.6 99.7

16 77.5 12.8 7.2 0.0 1.5 0.2 99.2

17 77.6 13.0 7.2 0.0 1.5 0.0 99.3

18 77.7 12.3 8.0 1.0 0.1 1.0 100.1

19 77.7 12.0 7.4 1 o 9 0.0 0.6 99.6

20 77.8 13.2 7.0 0.0 1.8 0.1 99.9

21 78.0 10.4 9.2 0.0 1.7 0.0 99.3

22 78.2 11.5 6.7 0.0 2.6 0.0 99.0

23 78.4 11.4 8.6 0.0 0.9 0.0 99.3

24 78.6 9.5 6.4 0.0 4.3 0.0 98.8

25 79.0 9.6 6.8 0.9 2.7 0.4 99.4

26 79.1 O 0

f—

6.4 2.9 0.0 0.7 99.7

27 79.9 9.4 7.6 0.0 1.9 1.4 100.2

28 80.0 9.1 6.3 0.0 3.4 0.2 99.0

29 80.0 9.4 7.5 0.0 1.9 1.1 99.9

30 80.1 10.4 9.0 0.0 0.0 0.0 99.5

31 82.0 6.9 6.6 0.0 3.5 0.0 99.0

32 83.0 7.5 5.8 0.2 2.5 0.2 99.2

33 83.7 7.8 7.9 0.0 0.1 0.4 99.9

34 83.9 7.6 3.9 3.8 0.0 0.5 99.7
1

2

3

4

56

78

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

TABLE 1

( continued )

CHEMICAL COMPOSITION OF TYPE III - CASTING GOLD ALLOYS

Gold

%

Silver

%

Copper

%

Palladium

%

Platinum

%

Zinc

%

Total

%

71 0 0 13.1 7.4 0.0 7.5 0.0 99.0

72.0 9.8 10.6 6.5 0.0 0.2 99.1

72.2 10.9 9.4 0.0 6.4 0.0 98.9

73 o 5 9.6 11.6 4.3 0.0 0.6 99.6

73.8 9.9 10.9 3.8 0.0 1.7 100.1

73.9 9.3 11.1 2.8 1.7 0.4 99.8

74.1 11.2 9.5 3.9 0.0 1.0 99.7

74.2 11.0 10.4 3.3 0.0 0.4 99.3

74.3 9.8 11.3 3.6 0.0 0.8 99.8

74.3 10.4 10.2 3.8 0.0 1.2 99.9

74.4 9.8 11.0 0.0 3.6 1.0 99.8

74.4 10.8 10.5 3.3 0.0 0.4 99.4

74.4 11.3 9.0 3.9 0.0 1.4 100.0

74.4 11.4 9.0 3.6 0.2 0.7 99.3

74.5 9.8 11.0 3.6 0.0 0.9 99.8

74.5 9.5 11.0 3.8 0.0 0.5 99.3

74.6 9.8 11.0 3.6 0.0 0.8 • 99.8

74.6 11.1 9.9 3.5 0.0 0.1 99.2

74.7 8.6 12.6 1.0 2.2 0.4 99.5

74.7 9.4 9.2 0.0 5.6 0.0 98.9

74.8 7.9 11.6 0.6 3.8 0.6 99.3

75.0 9.2 10.0 0.0 4.6 0.4 99.2

75.0 13.1 8.2 0.0 2.7 0.1 99.1

75.0 9.6 10.2 0.0 3.8 1.2 99.8

75.0 11.6 8.4 2.0 1.8 0.9 99.7

75.0 9.8 11.1 2.8 0.1 1.1 99.9

75.3 12.3 8.6 0.0 2.8 0.0 99.0

75.3 13.4 7.6 2.8 0.0 0.9 100.0

76.0 10.5 8.9 2.2 1.1 1.8 100.5

76.0 10.8 8.5 2.2 1.4 1.6 100.5

76.2 9.4 7.8 1.0 4.2 0.3 98.9

76.3 11.0 9.1 0.0 2.6 0.0 99.0

76.3 9.7 9.2 3.8 0.0 0.5 99.5

76.4 7.6 12.2 0.0 - 2.8 o.'o 99.0

76.8 7.4 12.0 0.0 2.8 0.5 99.5

77.3 8.6 10.2 0.0 3.0 0.0 99.1

77.7 10.4 9.4 0.0 1.7 0.0 99.2

78.3 7.7 7.4 2.4 2.8 0.0 99.5

78.8 7.5 7.8 0.0 4.4 0.6 99.1

78.9 7.9 7.4 0.0 4.4 0.4 99.0

79.0 6.5 11.2 0.0 2.6 0.0 99.3

79.2 6.0 7.7 2.8 2.6 2.0 100.3

79.2 8.8 10.1 0.0 1.0 0.6 99.7

79.2 8.1 7.1 0 o 0 5.2 0.2 99.8

79.8 5.2 8.3 0.0 5.2 0.6 99.1
1

2

3

4

56

78

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

TABLE 1

( continued)

CHEMICAL COMPOSITION OF TYPE IV - CASTING GOLD ALLOYS

Gold

%

Silver

%

Copper

%

Palladium

%

P latinum

%

Zinc

%

Total

%

62 „ 4 9.0 12.6 10.1 4.8 1.1 100.0

64.5 17.4 11.2 2.1 4.1 0.5 99.8

67.8 15.2 8.6 0.0 8.2 0.0 99.8

68.2 12.2 11.2 4.0 2.4 2.7 100.7

68.8 12.0 12.0 3.2 3.0 0.0 99.0

68.8 11.9 12.1 3.2 3.0 0.0 99.0

68.8 12.2 10.9 3.9 2.6 2.6 101.0

69.0 13.2 10.4 3.4 2.8 0.3 99.1

69.

0

12.2 11.5 3.4 2.8 0.8 99.7

69.0 11.9 10.8 4.4 2.1 1.6 99.8

69 o 0 11.1 11.6 4.2 2.4 1.4 99.7

69.1 9.8 13.4 0.0 5.4 1.1 98.8

69.1 11.2 11.3 5.0 1.6 1.8 100.0

69.1 11.9 11.0 4.0 2.4 2.1 100.5

69.2 10.3 13.3 3.9 2.0 0.5 99.2

69,4 11.1 11.0 4.0 2.6 2.5 100.6

69.6 8.1 13.2 3.0 4.9 0.4 99.2

69.6 11.4 12.3 3.4 2.0 0.3 99.0

69.6 10.6 13.4 2.0 3.0 0.9 99.5

69,7 8.8 14.0 0.0 5.6 2.0 100.1

69.8 8.0 15.4 3.8 1.2 1.0 99.2

69.8 10.2 12.5 2.5 3.1 2.0 100.1

69.9 11.2 12.6 3.0 2.0 0.9 99.6

70.2 10.2 12.8 3.9 1.1 1.4 99.6

70.2 10.2 13.3 0.1 5.0 0.6 99.4

70.3 9.4 13.0 1.0 5.2 0.3 99.2

71.2 8.8 14.2 4.0 0.2 0.4 93.8

71.9 9.6 13.8 2.0 1.2 C . 2 98.7
1

2

3

4

5

6

78

9

10

11

12

13

A1

N'

1

2

3

4

5

6

7

8

TABLE 1

( continued)

CHEMICAL COMPOSITION OF TYPE I - WROUGHT GOLD WIRES

Gold

%

Silver

%

Copper

%

Palladium

%

P latinum

%

Zinc

%

Nickel

%

Total

%

53o 6 8 „ 5 15.2 8.1 14 0 8 0.0 0.9 101.1

55 o 2 9.4 13.8 6.8 15 o0 0.0 0.9 101.1

55.7 9.9 13.8 6.7 14.0 0.0 0.9 101.0

56.1 9.7 12.9 7.4 14.1 0.1 1.0 101.3

56.4 6.6 13.2 7.8 17.4 0.2 0.1 101.7

57.0 7.6 11.4 8.2 17 o 6 0.4 0.0 102.2

58.4 12.2 10.2 4.1 15.7 0.6 0.0 101.2

60 o 6 9.4 15.0 6.6 7.9 0.0 0.2 99.7

61.4 11.7 10o 8 0.0 16.4 0.0 0.0 100.3

62.2 12 0 4 10.2 0.1 15.3 0.1 0.0 100.3

62 o 6 8.6 14.6 5.2 6.8 0.0 1.8 99.6

62.8 8.6 14 0 6 5.0 6.8 o.O 1.9 99.7

63.2 8.6 14.1 5.2 7.0 .0 1.8 99.9

CHEMICAL COMPOSITION OF TYPE II - WROUGHT 'GOLD WIRES

Gold

%

Silver

%

Copper

%

Palladium

%

Platinum

%

Zinc

%

Nickel

%

Total

%

60.2 10.0 14.0 10.4 4.1 0.1 1.8 100.8

62.3 17.5 13.8 4.2 1.6 0.0 0.0 99.4

64.2 10.4 19.6 0.0 1.8 0.4 : 2.0 98.4

64.2 8.4 18.6 0.0 1.3 0.8 6.2 99.5

66.6 21.4 10.2 0.5 0.0 0.0 1.8 100.5

66.7 14.0 13.2 0.0 3.7 0.0 1.9 99.5

67.0 11.4 14.1 5.0 0.8 1.7 0.0 100.0

67.1 12.4 11.8 0.1 6.5 0.4 1.4 99.7
TABLE 2

REPRESENTATIVE COMPOSITIONS* OF CASTING GOLD ALLOYS

Number

Type of Au Ag Cu Pd Pt Zn

Alloys % % % % % %

16 87.3 8.4 4.1 0.0 0.1 0.1

I

3 89.7 4.9 3.9 0.0 1.3 0.2

9 83.4 9.7 4.6 2.0 0.0 0.3

1 80.6 11.7 4.4 1.9 0.4 1.0

2 82.2 9.2 8.4 0.0 0.0 0.2

II

13 79.7 10.7 7.1 0.0 2.3 0.2

17 77.4 12.5 7.7 1.9 0.0 0.5

2 78.6 10.5 7.1 1.4 2.2 0.2

19 77.0 9.4 9.5 0.0 3.8 0.3

III 17 74.6 10.6 10.2 3.8 0.0 0.8

9 76.2 9.1 9.4 1.9 2.4 1.0

IV 4 69.6 11.1 12.4 0.0 6.0 0.9

24 69.3 11.1 12.4 3.6 2.6 1.0

^Adjusted to total 100.0%
TABLE 3

COMPOSITIONS* OF CASTING GOLD ALLOYS BY TYPE

Type

Number

of

Alloys

Au

%

Ag

%

Cu

%

Pd

%

r+ Zn

%

I 29 86.1 8.6 4.2 0.7 0.2 0.2

II 34 78.5 11.5 7.5 1.1 1.0 0.4

III 45 76.0 9.8 9.7 1.8 2.1 0.6

IV 28 69.3

i

—

1

•

i

—

1

«H 12.4 3.1 3.1 1.0

*Ad justed to total 100.0%
TABLE 4

COMPOSITION* OF WROUGHT GOLD WIRE

Type

Number

of

Alloys

Au

%

Ag

%

Cu

%

Pd

%

Pt

%

Zn

%

Ni

%

6 58.8 9.9 11.7 4.5 14.9 0.2 0.0

I 4 54.6 9.3 13.7 7.2 14.3 0.0 0.9

3 63.1 8.6 14.5 5.1 6.9 0.0 1.8

2 64.9 14.3 14.0 4.6 1.2 0.8 0.0

II 5 65.2 13.6 13.8 2.2 3.2 0.2 1.8

1 64.5 8.5 18.7 0.0 1.3 0.8 6.2

*Adjusted to total 100.0%
TABLE 5

COMPOSITION* OF WROUGHT GOLD WIRES BY TYPE

Type

Number

of

Alloys

Au

%

Ag

%

Cu

%

Pd

%

Pt

%

Zn

%

Ni

%

I 13 58.4 9.4 13.0 5.5 12.9 0.1 0.7

II 8 65.0 13.2 14.5 2.5 2.5 0.4 1.9

*Ad justed to total 100.0%
TABLE 6

COMPARISON OF AVERAGE COMPOSITIONS OF

CASTING GOLDS AND WROUGHT GOLD WIRES

Type Year Number Au

%

Ag

%

Cu

°/o Pd

%

Pt

%

Zn

%

Ni

%

Total

Casting

Gold

19281 30 72.2 9.8 9.4 1.9 5.8 0.5 0.3 99.9

19683 136 77.1 10.2 8.5 1.7 1.6 0 o 5 0.0 99.6

Wrought

Gold

Wire

1928 2 and

1932

33 64.6 8.5 9.7 3.6 13.1 0.2 0.0 99.7

19683 21 61.1 10.9 13.6 4.4 9.0 0.2 1.2 100.4

1 These averages were calculated from Table 10 of Coleman (2)

omitting the compositions of the gold solders.

2 These averages were calculated from Table 1 of Coleman (2)

omitting alloys "B" and "P" and from Table 1 of Paffenbarger

et al (3) omitting alloy "O".

3 These averages were calculated from Table 1 of this paper

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