The metal materials used for eyeglasses frames are divided into three categories: copper alloys, nickel alloys and precious metals.
1. Cupronickel frame (copper-zinc alloy)
The main components are copper 64%, zinc 18%, and nickel 18%. The frame material is the cheapest and easy to process. Electroplating is mainly used to make hinge brackets, small parts and low-end frames.
2. High nickel alloy frame
Nickel content is as high as 80% or more, mainly nickel-chromium alloys, manganese-nickel alloys, etc. High-nickel alloys have better corrosion resistance, and in addition, the material has good elasticity.
3. Monel frame
Nickel-copper alloy, with a nickel content of about 63%, copper and 28%, in addition to iron, manganese and other small amounts of metals, especially: corrosion resistance, high strength, strong welding, and the most used materials for mid-range racks.
4. Gold-clad frame
The process is to add solder or direct mechanical bonding between the surface metal and the substrate. Compared with electroplating, the surface metal layer of the cladding material is thicker, and it also has a bright appearance, good durability and corrosion resistance.
5. K gold frame
Generally 18K gold, indicating that the content of pure gold 24K in the frame is 18/24. If it is expressed by 750/1000, it means that the silver, copper and other substances are 250/1000. If the weight of 18K gold glasses is 40 grams, the gold content is 18÷24×40=30 grams.