Nickel Silver: Characteristics, Uses and Problems

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• In the 1840s, nickel superseded copper as the material of choice for silver plating; nickel was harder, stronger and more durable than copper.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.