Nickel Silver: Characteristics, Uses and Problems
- Procedure code:
- 501017G
- Source:
- Jester, Tom, ed. Twentieth Century Building Materials: History and Conservation. Los Angeles: The Getty Conservation Institute, 2004.
- Division:
- Metals
- Section:
- Metal Materials
- Last Modified:
- 08/09/2016
References
- Gayle, M., Look, D. and Waite, J. Metals in America's Historic Buildings: Uses and Preservation Treatments. Washington, DC: National Park Service, 1992.
- Zahner, L. W. Architectural Metal Surfaces.New York: Wiley 2004.
For guidance on cleaning nickel silver, see "General Methods of Cleaning Nickel Silver".
Characteristics of nickel silver
- A copper-nickel-zinc alloy that contains no silver.
- Contains 50-80 percent copper, 5-30 percent nickel and 10-35 percent zinc; it may also contain small percentages of lead, tin and manganese.
- Higher amounts of copper make the nickel silver metal more ductile and more resistant to corrosion.
- Higher amounts of nickel make nickel silver look more like silver.
- Higher amounts of zinc slightly improve corrosion resistance, lower the melting point, raise the nickel silver's strength and hardness, but decrease its ductility.
- Has many of the same characteristics as brass and bronze.
- Has existed for over 2000 years.
- May be wrought, cast, rolled, stamped, forged, drawn, extruded and machined.
- Silvery-white in color.
- Takes a high polish.
- Extremely hard.
- Abrasion-resistant.
- Malleable.
- Ductile.
- Nonmagnetic.
- Highly resistant to environmental corrosion.
- Suitable for soldering and welding, depending on the presence of lead.
- Develops a protective oxide, or patina when exposed to oxygen; the patina is brownish-green when exposed for long periods of time.
- Called copper-nickel or false copper in the late 1600s due to the reddish color of the ore, but lacking the ductility and malleability of copper.
- Discovery that the silver ore contained nickel occurred in the mid-1700s; established as a new elemental metal by Aksel Frederik Cronstedt.
- A German version called new silver was marketed in the 1800s.
- Called German silver in England up until World War I; called nickel silver after that time.
Typical Uses
Typical historical uses for nickel silver include:
- Nickel alloys commonly used for coins and ornamental objects.
- Tableware and plated objects.
- In the 1840s, nickel superseded copper as the material of choice for silver plating; nickel was harder, stronger and more durable than copper.
- Electroplating became the most fundamental application of nickel silver in the early 1900s; some uses included costume jewelry, keys, soda fountain and bar equipment, cigarette cases, automobile radiators and hub caps.
- Used for more decorative and structural elements in the 1920s, such as decorative panels, doors, grilles, railings, plumbing fixtures, plaques, trim and divider strips in terrazzo floors.
- Popular for door knobs, handrails and push plates because of its abrasion-resistance.
- Use of nickel silver declined in the 1950s.
- After World War II, stainless steel and aluminum replaced the use of nickel silver due to their low production cost.
- Most buildings containing nickel silver were constructed in the 1920s and 1930s.
Typical current uses for nickel silver include:
- Industrial and electrical purposes.
- Cast and wrought forms of the metal are occasionally found in building designs.
- Manufactured today only in silver-white or white with a yellow tint; shades of pale yellow, green, pink and blue can also be produced by varying the nickel content; custom orders can also be made to match an older nickel alloy finish if necessary.
Natural or Inherent Problems
- Corrosion: The zinc content of Nickel Silver makes the alloy metal sensitive to acid and sulfur pollutants and will tarnish in their presence.
- Stress Corrosion Cracking: Tensile strength combined with exposure to a corrosive environment; factors affecting this type of deterioration include temperature, metal composition and metal structure.
- Sensitive to chromic and nitric acids due to its high copper content.
Vandalism or Human-Induced Problems
- Scratches and dents.
- Susceptible to mechanical deterioration such as fatigue, but not creep.