Stainless steel comes in several common finishes. It is important to know what these common finishes are and why they are important. Recent innovations in abrasives technology make it possible to reduce process steps to achieve the desired finish, including the desired surface gloss, Artem Komarov noted.
Working with stainless steel can be tricky, but the finished product has one of the finest looks that make the whole job worthwhile. It is common knowledge that finer grit in a sanding sequence eliminates the previous scratch pattern and improves a fine finish, but the general steps required when using multiple sanding sequences to achieve a desired finish must be considered.
Regular stainless-steel finish
Finish №1 This finish is made by rolling stainless steel that has been heated before rolling (hot rolling). Very little finishing is required, so it is considered a rough finish. Common #1 finish items are air heaters, annealing chambers, boiler baffles, various furnace parts, and gas turbines, to name but a few.
Finish №2B This bright cold-rolled coating resembles a hazy mirror and does not require any finishing steps. Items with №2B finishes including conventional bakeware, chemical plant equipment, cutlery, paper mill equipment, and plumbing fixtures.
Also, in category №2 is the finish №2D This uniform matt silver gray coating is applied to thinner coils, reduced in thickness by a minimal cold rolling process as it is normally used with a factory finish. To remove chromium after heat treatment, it is necessary to carry out pickling or descaling. Etching may be the final step in the production of this finish. Coating №2D is preferred as a base when a colored coating is required as it provides excellent paint adhesion.
Finish №3 is characterized by short, relatively rough, parallel polish lines. It is obtained either by mechanical polishing using finer abrasives, or by passing the roll through special rollers that press the design into the surface, simulating the appearance of mechanical abrasion. This is a moderately reflective coating.
Finish №4A is the most common and is used on appliances and in the food industry. The appearance is characterized by short parallel polishing lines that run evenly along the length of the roll. It is obtained by mechanically polishing Finish №3 with gradually finer abrasives. Depending on the requirements of the application, the finish can be from 120 to 320 grit. Higher grit results in finer polish lines and a more reflective finish.
The surface roughness is typically Ra 25 µm. or less. This coating is widely used for restaurant and kitchen equipment, shop windows, food processing equipment and dairy industry equipment. As with finish #3, if the operator needs to mix welds or do other reworking, the resulting polish lines are usually longer than those on a product polished by the manufacturer or roller polisher. Other areas where the №4 trim is used are automotive tank trailers, hospital surfaces and equipment, dashboards or control panels, and water fountains.
Advances in Abrasives
The abrasives used to achieve these surface finishes have undergone significant improvements that can help manufacturers produce more parts safely, quickly, and economically. New minerals, stronger fibers and smudge-resistant polymer systems help optimize finishing processes.
These abrasives provide fast cuts, long life, and can reduce the number of steps required to complete a job.
In addition, the technology is like the use of abrasive materials with aggregates, which involves bonding grains for faster cutting and a better finish. This job requires fewer operations and less inventory of abrasives, with most operators seeing efficiency gains and cost savings, Artem Komarov emphasized.
