As a premier stainless steel vendor in the Northeast, the team at Alliant Metals is often asked about aspects of metal finishing. One of the most common inquiries we have regards the different types of stainless steel finishes. This article will provide you with a brief overview of a few of these finishes.
Mill finish refers to the finish (or texture) of metal after it exits a rolling mill. This includes sheet, bar, plate, or stainless structural shapes. The texture typically is rough and lacks any shine. Further, there may be visible spots of oxidation. Thus, most mill finish surfaces are further machined or treated with a polishing process before they’re considered complete.
2B is a term used to describe the most widely used stainless steel finish. Produced similar to the 2D, the difference lies within the final light cold rolling pass. 2B is a term used to define a “smooth, moderately reflective cold-rolled annealed and pickled or descaled finish typically produced by imparting a final light cold-rolled pass using polished rolls,” according to the ASTM A480 standard.
A 2B mill finish results in a surface similar to that of a cloudy mirror. The most common uses for this type of finish is for plumbing fixtures, industrial equipment, automotive needs, and aerospace.
Attained by polishing the stainless steel with fine abrasive belts, No. 4 finished stainless steel can vary between manufacturers. This variation is due to the use of different belt and grit sizes. The higher the grit, the finer the lines, and higher reflective properties the product will have. However, No.4, also known as 180 Grit, will always produce a duller result than the 2B mill finish. This general-purpose finish is typically utilized for kitchen equipment.
As the name implies, a mirror finish is one with a bright, clear reflective surface. With extensive buffing around fifteen to twenty minutes, grit lines are brought to a visibility of next to none. Although the ending result is the closest to a mirror finish, a dull glaze will still be present which is why this polish is also referred to as “dairy finish.” Due to the ability to prevent contamination, this finish is the ideal solution for clean rooms and restaurants.
For more information on the variety of metal polishing processes available, contact the experts at Alliant Metals. Our team has become the go-to stainless steel vendor. From exceptional customer service to providing the highest-quality materials, you can have confidence when you work with Alliant Metals. Call today at (800) 543-1453.