Data Analysis: Surface Roughness of Mirror Stainless Steel

The term “mirror stainless steel plate” indeed refers to the surface finish of stainless steel, but it encompasses a range of grades with varying degrees of reflectivity and smoothness. These grades are typically defined by their surface roughness, measured in microinches (μin) or micrometers (μm), and correspond to different surface finishes achieved through specific polishing processes.

The “K number” system, while commonly used in the industry, is not a standardized measurement and can lead to inconsistencies in interpretation. For more precise differentiation, it’s beneficial to use internationally recognized standards such as the ASTM A480 or EN 10088-2, which provide more accurate and consistent descriptions of surface finishes.

For example:

• 8K finish typically corresponds to a surface roughness of approximately 0.05-0.1 μm Ra (Roughness average).
• 12K finish generally achieves a surface roughness of about 0.02-0.05 μm Ra.

However, these values can vary between manufacturers and specific polishing techniques employed. To ensure precise specification and quality control, it’s recommended to:

1. Use quantifiable roughness parameters (Ra, Rz, etc.) measured with profilometers.
2. Specify the desired gloss level using a glossmeter (measured in Gloss Units).
3. Consider additional characteristics like DOI (Distinctness of Image) for highly reflective surfaces.

For critical applications, it’s advisable to request sample plates or perform on-site inspections to verify the exact surface finish meets the required specifications. This approach ensures clarity in communication between suppliers and end-users, reducing the potential for misunderstandings often associated with the less precise K number system.

We have created a list to help identify different grades of stainless steel.