Finishes of Stainless

Stainless steel countertop finishes may vary depending on the ¹grade of stainless steel used, ²method of original graining, and the ³actual grain or grit finish.

Eskay Metal Fabricating uses prime 304 #4 stainless steel for all our custom countertops. Let me explain what these numbers mean:

¹ 304 stainless is made of 18% Chromium and 8% Nickel, giving it corrosion resistance and protection from staining, pitting, rusting, and discoloration.

If a product is manufactured with 400 series stainless (commonly used in inexpensive cookware, utensils, etc.) the hue or appearance may have a darker or even “blue” tint when compared to 300 series. A simple test is to hold a magnet up to the stainless surface – if it is attracted to the product, more than likely it is 400 series stainless. This series is also more subject to corrosion and or rust if exposed to acidic foods or harsh chemicals.

²Graining methods can be either mechanical or manual with a random or straight grain.

Most fabricators and manufacturers will order pre-polished material if their processes will not disturb the final finish. Finishes are generally applied while still on the coil, utilizing a series of high speed brushes (i.e. Scotchbrite) to create the final grain desired. This type of finish has a random, short stroke grain that is very consistent throughout. A plastic or PVC coating is applied for temporary protection.

Manual polishing is applied after welded joints have been ground or where forming has marred the finish. Generally, this process includes as series of polishing (i.e. Scotchbrite) pads or a multi-compound type pad or wheel to blend the finishes together. This type of finish has a longer grain stroke and may appear to have a brighter finish than the pre-finished material.

³The #4 is the polish rating, or in this case, a finish range of 150 to 180 grit.

A #4 finish is the most common of stainless steel cosmetic finishes. It appears as a fine, single directional grain and is also known as a brushed or satin finish. A #3 finish also shows up in today’s market, most common on refrigerators or stove fronts. This grain is slightly more course, finishing in the range of 100 to 120 grit. Placed side by side, the two finishes are noticeably different. A simple test is to run your fingernail perpendicular to the grain. Your fingernail will generally leave a “mark” on a #3 finish and not so on a #4 finish.

by Jeff Subra, President of Eskay Metal Fabricating