Gold plating
Nu-Metal Finishing certifies conformance to MIL-G-45204 for all types, grades and thicknesses:
# Type I 99.7% gold minimum (Grades A,B or C) # Type II 99.0% gold minimum (Grades B,C) # Type III 99.9% gold minimum (Grade A only)
Nu-Metal Finishing is able to plate gold over all conductive materials including Nitinol, stainless, titanium, Thermkon, Silvar, molybdenum and other refractory metals.
For more information on Nu-Metal Finishing's gold plating processes, call 1.800.303.1050 or email us today.
Specifications Summary
MIL-G-45204
covers gold plating on various metals.
Sample callouts:
Gold
Plate per MIL-G-45204, Type III, Grade A, 100 µin
Gold
Plate per MIL-G-45204, Type III, Grade A, Class 2
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Gold Purity
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Type I
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Type II
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Type III
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99.7%
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99.0%
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99.9%
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Hardness
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Grade A
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Grade B
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Grade C
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Grade D
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<
90 Knoop
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91-129
Knoop
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130-200
Knoop
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>
200 Knoop
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Thickness
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Class 1
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Class 2
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Class 3
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Class 4
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Class 5
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50
µin
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100
µin
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200
µin
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300
µin
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500
µin
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Heat Treat
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Should
be specified by customer if stress relief (pre-plate) or
embrittlement relief (post-plate) is desired.
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Underplate
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Should
be specified by customer. If unspecified, Nu-Metal will use
nickel as a diffusion barrier/underplate.
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NOTES: The
assignment of purity is neither increasing nor decreasing with the
type number and this has led to much confusion in the use of this
specification. The purity and hardness cannot be specified
independently: Type III gold must be Grade A because the purity
specification precludes addition of other metals to harden the
deposit. Type II gold can only be Grade B, C or D. Type I gold can
only be Grade A, B or C. Nu-Metal offers this process with or without
CoC.
ASTM B
488
covers gold plating on various metals.
Sample callouts:
Gold Plate per ASTM B 488, Type III, Grade A, 100 µin
Gold Plate per ASTM B 488, Type III, Grade A, Class 2
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Gold Purity
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Type I
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Type II
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Type III
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99.7%
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99.0%
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99.9%
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Hardness
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Grade A
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Grade B
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Grade C
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Grade D
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<
90 Knoop
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91-129
Knoop
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130-200
Knoop
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>
200 Knoop
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|
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Thickness
|
Class
1
|
Class
2
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Class 3
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Class 4
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Class 5
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50
µin
|
100
µin
|
200
µin
|
300
µin
|
500
µin
|
|
|
Heat Treat
|
Should
be specified by customer if stress relief (pre-plate) or
embrittlement relief (post-plate) is desired.
|
|
|
Underplate
|
Should
be specified by customer. If unspecified, Nu-Metal will use
nickel as a diffusion barrier/underplate.
|
NOTES: The
ASTM Specification was originally issued with a logical assignment of
Type Number to Purity; unfortunately, this caused mass confusion and
in 2001 the Specification was updated (ASTM B 488-01) to align with
the older Mil spec. We still see drawings with incorrect Type call
out dating back to the earlier ASTM specs. As with the Mil spec, the
purity and hardness cannot be specified independently: Type III gold
must be Grade A because the purity specification precludes addition
of other metals to harden the deposit. Type II gold can only be Grade
B, C or D. Type I gold can only be Grade A, B or C. Nu-Metal offers
this process with or without CoC.
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