Rough surfaces should be avoided

Only a few subjects are as big of a source of differed opinions than polished and glass-blown surfaces. Architects and designers love the beautiful, polished surfaces and it is almost impossible to imagine a decorative stainless construction without either a polished or glass-blown surface. Fridges, cooker hoods and bannisters – all of these are either polished or glass-blown and the case is the same with the inside surfaces of a lot of tanks. However, is the most beautiful surface always the best in terms of functionality?

 

Unfortunately, no. Compared to the “boring” cold-rolled standard surface (“2B”), polished and especially glass-blown surfaces are actually quite rough. From experience, this results in at least two disadvantages compared to the less flamboyant 2B-surface:

 

• The corrosion resistance is lower for the polished/glass-blown surface
• The polished/glass-blown surface is more difficult to clean – even though the roughness (as R_a) is under the limit of 0,8 µm

 

Therefore, if you decided to polish or glass-blow, it is important to accept that you weaken the steel in all functional ways. This, among other things, entails that you risk having to use higher alloyed steel than normal to compensate for the low corrosion resistance – or intensify the cleaning to compensate for the fact that impurities easily can find hiding spots in the polished/glass-blown surfaces.