K gold refers to gold and other metals mixed together alloy, because of its English is Karat gold, so referred to as K-gold. The precious metal part, pure gold is 24K, but the pure gold is too soft to make the watch, must mix other metals to strengthen the hardness, generally to the silver, the copper and the palladium primarily, but regardless of the mix which metal, the proportion of pure gold accounted for 75%. With gold, silver and copper ratio, can produce five kinds of different color of the material, respectively, n to indicate the high and low copper content, such as the highest copper content of red gold to 5N, and platinum is the right word is white K gold.
From stainless steel and 18K gold material with each other to use, presenting a unique two-color aesthetic.
Gold its case is stainless steel, outsourcing a layer of gold alloy, by mechanical rolling into a whole, the thickness of Micron as the unit of measurement, 1 microns equal to 1/1000 mm. Up to 10 to 15 microns thick, typically only 2 to 3 microns.
Electroplating (gilded, thank Wiiasa brother, Electroplating should be placed in the properties of precious metals, the hearing is explained below) electroplating is a modern watch in the common case decoration method, electroplating technology was rising in the 70 's, because the plating uniformity is firm, less than gold cost and not easy to fall off, and no forged yellow shell discoloration, rust, it is possible to eliminate the two quickly out of the market.