Gold Plating

Gold Specifications MIL-G-45204 & ASTM B 488 NADCAP Certified

Metal Finishing

Specialty Process

Information

Hi-Tech Specs

We plate gold to Military or ASTM Specification only. We do not do decorative jewelry plating.

 

Certifications
ISO 9001:2000/
AS9100 Rev B
NADCAP Certified

Gold Plating For Exceptional Corrosion Resistance & Excellent Conductivity

What Is Gold Plating?

Gold plating is the process of electrolytically depositing a layer of gold onto a part. Plated gold deposits can range in color from yellow to orange and be bright or dull (matte) in appearance.

Exceptional Corrosion Resistance / Excellent Conductivity

Engineers and manufacturers often use gold plating because of its exceptional resistance to corrosion. Gold plating also has low contact and electrical resistance making it ideal for electronic applications. Many electronic parts, such as connectors or circuit board components, are gold plated to provide maximum corrosion resistance while maintaining excellent conductivity and solderability.

Gold Plating Specifications

MIL-G-45204 and ASTM B 488 are the prime gold plating specifications. They define three types of gold deposits produced by electroplating. Types I, II, and III refer to purity while grades A,B,C,D refer to Knoop hardness.

Gold – MIL-G-45204 / Types I, II, III
ASTM B 488 / Types I, II, III

  • Type I: 99.7% gold 
  • Type II: 99.0% gold 
  • Type III: 99.9% gold

Gold – MIL-G-45204 / Grades A,B,C,D 
ASTM B 488 / Grades A,B,C,D

  • Grade A: Hardness range of 90 or less Knoop 
  • Grade B: Hardness range from 91 to 129 Knoop
  • Grade C: Hardness range from 130 to 200 Knoop
  • Grade D: Hardness range of 201 or more Knoop

The most common alloying elements in Types I and II are nickel and cobalt.

Gold Plating Over Copper Or Silver Substrates

In many gold-plating applications where the substrate is made of copper or silver, a barrier layer of nickel is applied between the substrate and the gold to prevent the copper or silver ions from diffusing into the gold layer.

Soft Pure Gold For The SemiConductor Industry

Type III gold (99.9% gold is usually referred to as “pure”) is used in the semiconductor industry when parts need to be wire bonded during fabrication.

Gold Types For The Electronic Industry

The Type 1 and Type II gold deposits are harder and are alloyed with either cobalt or nickel as deposited. These alloys have a much higher hardness and are more appropriate for contacts and connectors.

Interesting Facts About Gold & Gold Plating

  • Gold plated jewelry can have deposits as low as 10 karat purity (out of 24). Gold plated colors such as “green or white” gold can be produced.
  • Gold was probably the first metal worked by man. It can be found in a pure state and can be hammered and worked easily into decorative jewelry pieces.
  • In nature, gold is often found alloyed with silver and to a lesser degree with lead.
  • Giving something the “acid test” arose from a method that was used to see if something was really made of gold.
  • 24 karat gold skin treatments are offered by some spas. Real gold powders or flakes are used and miraculous results claimed. The only true result is the reduction of one’s bank account. Gold is inert and therefore cannot accomplish anything beneficial.

Call us today at 1-617-389-3400 for a speedy quotation on your metal finishing project.