Ian's Guide to Industrial Manufacturing

Stainless Steel—The Material That Still Needs Finishing

Because of its name and the well-known fact that stainless steel looks pretty attractive as soon as it is produced, some manufacturers who use it in their products don't consider finishing it at all. This is a mistake because stainless steel products look very good when they have been finished properly. Few design engineers would specify chrome in a product, for example, that is not highly polished or buffed. Likewise, the various industrial treatments available for stainless steel should not be overlooked when updating an existing product line or designing a new one.

What are the common stainless steel finishes in use today by Australian firms?

Sandblasting Stainless Steel

A highly effective technique with a number of grades of stainless steel, a sandblast treatment on a finished product made from this metal will offer it a refined look. An abrasive treatment, sandblasting does away with any imperfections that may have been formed on the outer surface of the steel during manufacturing. As a result, products like stainless steel balustrades, bollards and cycle racks will appear shinier and newer. If your product is fashioned from a casting process then all of the little marks that are left behind can be simply blasted away using high-pressure jets of sand.

Mill Finishes

This sort of finish is achieved when stainless steel is made rather than being applied to it afterwards. A mill finish can be achieved with plate, tubular and sheet stainless steel. This approach is best when a deliberately dull finish is wanted which won't reflect much light or stand out. It tends to be used with road transportation infrastructure products, for instance, because they produce little glare.

Acid Finishes

Applying acid to sections of stainless steel removes the outer few layers of molecules. The degree to which the steel underneath is exposed depends on the strength of the acid application and how long it is left to do its work. Manufacturers tend to use this process to refresh the finish of a stainless steel component which has rusted a little due to contact with other oxidising metals, such as iron.

Painting Stainless Steel

If you don't want the natural look of the metal to be apparent, then it is possible to paint stainless steel. Any colour is possible but you will need to apply a coat of metalwork primer beforehand if the paint is to survive for long outside. Kiln-dried paint applications are the best for industrial products, such as lighting columns and machinery because it causes the painted finish to dry evenly without dripping.