Nickel silver is first known in China, and was known in the west from imported wares called “paktong” (白銅) , it is named for its silvery appearance, but contains no elemental silver.
If your metal frames caused a reaction, nickel is usually the culprit because most metal frames are made of a nickel alloy. Other metals used include aluminum, stainless steel, titanium, zinc, copper, beryllium, gold and silver. Stainless steel, titanium, gold and silver are usually hypoallergenic.
Nickel Silver Frame – Alloy of copper, nickel, and zinc. Many varieties according to the percentage of each element in its composition, but the usual formulation is (60% / 20% / 20% )Copper / Nickel / Zinc. Most of the frames in the market made of this kind of metal. Nickel silver is able to be enameled with various colors. This frame can be decorated with epoxy wire on the eye rim. The life time of nickel silver is not very long since it can be affected by the wearer’s sweat. It has been said that nickel can cause skin cancer, so it might be good to avoid this kind of frame, especially for one who has sensitive skin.
• 80% of metal eyeglasses use all or part of this material. Silver nickel is economical and easy to manufacture with a high precision, since it is hard. Its drawback is its high nickel content, which requires a protection layer. It is often associated with monel, which is used to make the front part of the frame.
• It is frequently used to make machined elements (pivot pins, tenons, rims…) or matrixed elements (temples, bridges, endpieces).
Pros : Extremely durable and flexible. Endless color and design options. Easy to warp and polish, can be used for thick parts.
Cons : Less resistant than monel. Heavy, corrosive, allergic reaction is possible.
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