As we all know, the corrosion resistance of stainless steel depends on its alloy composition (chromium, nickel, carbon, silicon, manganese, etc.) and internal organization, the decisive role is played by the chromium alloy element, which can form a passivation film on the surface of the steel, so that the metal is isolated from the outside world and will not produce oxidation reactions to improve the corrosion resistance of steel, so another name for stainless steel is chromium-nickel alloy steel.
8K in the "8" refers to the proportion of metal alloy composition (304 stainless steel mainly refers to the content of nickel elements), "K" refers to the polished reflectivity of the grade (K is the mirror reflective grade). 8K mirror is also the chromium-nickel alloy steel embodied in the Mirror grade.
In addition, due to the different requirements of customers for the surface fineness of stainless steel, on the basis of 8K extended 6K, 10K, 12K, etc.. And the larger the number, the higher the mirror fineness. 6K refers to coarse grinding and polishing mirror plate, its effect is a little worse than a mirror; 10K refers to fine grinding and polishing mirror plate, comparable to ordinary mirrors; 12K refers to ultra-fine degree grinding and polishing mirror plate, can meet the optical purposes.
However, no matter which surface fineness, which stainless steel mirror plate, so far there is no unified standard, just the higher the brightness, the greater the reflectivity, the less surface defects (white spots, pinhole, orange peel pattern, water ripples, etc.), the more it can be recognized by customers.