Although mirror stainless steel is called mirror, it also has grades. This grade refers to the roughness of the stainless steel surface. Different grades represent different surfaces. For example, 8k and 12k of mirror stainless steel represent different surface effects.
Stainless steel surface finish grade 14 Ra 0.012~0.03μm 14k mirror stainless steel, excellent surface effect (super fine polished stainless steel)
Stainless steel surface finish grade 13 Ra 0.015~0.02μm 12k mirror stainless steel, excellent surface effect (super-fine polished stainless steel)
Stainless steel surface finish grade 12 Ra 0.02~0.16μm 10k mirror stainless steel, excellent surface effect (fine polished stainless steel)
Stainless steel surface finish grade 11 Ra 0.1 ~0.2μm 8k mirror stainless steel, good surface effect (fine polished stainless steel)
Stainless steel surface finish grade 10 Ra 0.2 ~0.3μm 6k mirror stainless steel, BA stainless steel, as shipped from the factory
Stainless steel surface finish grade 9 Ra 0.4 μm 4k has almost no brightness, also called 2B surface (matte surface) without brightness
Stainless steel surface finish grade 8 Ra 0.8 μm No mirror effect, can micro-discriminate machining marks, unpolished surface
Stainless steel surface finish Grade 7 Ra 1.6 μm No mirror effect, the direction of processing marks can be identified, unpolished surface
Stainless steel surface finish grade 6 Ra 3.2 μm No mirror effect, no machining marks, unpolished surface
Stainless steel surface finish grade 5 Ra 6.3 μm No mirror effect, visible processing marks, unpolished surface
Stainless steel surface finish grade 4 Ra 12.5 μm No mirror effect, visible machining marks, unpolished surface
Stainless steel surface finish grade 3 Ra 25 μm No mirror effect, very rough surface, very obvious machining marks, unpolished surface
Stainless steel surface finish grade 2 Ra 50 μm No mirror effect, very rough surface, very obvious machining marks, unpolished surface
Stainless steel surface finish Grade 1 Ra 100 μm No mirror effect, very rough surface, very obvious machining marks, unpolished surface
The higher the grade of stainless steel, the better the surface effect of stainless steel. The higher the grade, the brighter, smoother and smoother the surface.
