A Guide To Stainless Steel Finishes

Stainless steel has an enormous variety of applications, so there are many finishes to choose from. The aim of these stainless steel finishes is to ensure quality, and they offer different levels of reflectivity and durability. In this guide, we will look at the full range of stainless steel finishes.

Here Are The Different Stainless Steel Finishes:

This is a rough, durable finish achieved by hot rolling. It starts with heat treatment for a microstructure we call annealing, aligning the material with mechanical property requirements. This combination of annealing and hot rolling results in a dark, varied appearance known as a scale, which is removed with chemical agents to create superior corrosion resistance. This finish is common for things applications that don't require any reflection.

This is a very common stainless steel finish that is non-reflective and smooth in nature. The appearance is dull and unreflective, so it is not commonly used to be aesthetically appealing, but it is a very cost-effective option. The stainless steel is rolled through a special roller for a smooth, less pitted surface, before being descaled in an acid solution and polished for greater smoothness. It is commonly used for chemical and pharmaceutical equipment.

This is the 120-grit option for an abrasive, one-directional course. There will be a peel-off protective layer on one side, and the finer polishing techniques require special coils/rolls. What results is a linear grain pattern with a moderate reflective finish and roughness average (Ra) of 40 or less. Commonly used for food production equipment and scientific apparatus.

This differs from No. 3 with its gradually finer abrasives. It can end with a grit of 150-320, with greater reflection on the higher grit numbers. The Ra will be 25 micro-inches or less and the finish will be highly reflective. You will find No. 4 finishes around food and restaurant equipment, hospital surfaces and things like highway tank trailers.

These are highly reflective - almost mirror-like. It requires polishing a No. 4 finish with a 320+ grit and extensive buffing. The polishing lines can be easily seen, and the resulting aesthetic is commonly used for things like ornament trims or wall panels.

These are extremely bright and reflective - the most reflective by ASTM standards. Buffing is extensive to make grit lines all but invisible - the longer it is polished for, the less likely any imperfections will be visible. The elegant aesthetic makes this finish ideal for wall panels, mirrors, reflectors and other highly-visible things.

The BA and TR finishes look similar to the No. 8 but the finish is less clear. That mirror-like quality will not be so apparent, but the reflective finish is produced without the need for further processing, so may be more cost-effective.

If you have any questions about stainless steel finishes, contact Sheet Metal Improvements today and our friendly team can help. We are your local stainless steel experts in the Gold Coast region and we are happy to help with any queries you may have.