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July/August 2014 11 continued on page 18 Terms You Should Know Alloy: A substance that is a mixture of two or more metals, or of a metal with a nonmetallic material. The term alloy is often used interchangeably with grade or type when referring to stainless steel. The most common alloys used in foodservice are 201, 301, 304, 316 and 430. Austenitic: Non-magnetic stainless steels that contain nickel and chro- mium sufficient to develop and retain the austenitic phase at room tempera- ture. Austenitic stainless steels are the most widely used category of stain- less steel. Ferritic: Magnetic stainless steels that have a low carbon content and contain chromium as the main alloy- ing element, usually between 13 per- cent and 17 percent. It is the second most widely used stainless steel. Gauge: The thickness of a certain stainless steel. Each gauge is actually a range of thickness because steel rolling mills have natural fluctuations and tolerances in the product they produce. The lower the number the thicker the metal, so 14-gauge stain- less would be thicker than 18-gauge. Galvanized: Steel coated with a thin layer of zinc to provide corrosion resistance. In foodservice, galvanized steel is often used for structural sup- port or in hidden areas (such as inside the guts of a refrigerator). It is much less expensive than stainless steel and thus attractive to end users. Martensitic: A small category of magnetic stainless steels typically containing 12 percent chromium, a moderate level of carbon, and a very low level of nickel. Stainless Steel: Corrosion-resistant steel of a wide variety but always containing a high percentage of chromium. (The composition needs to contain at least 10.5 percent to be a stainless steel.) Some standard grades of stainless steel also have 3.5 to 22 percent of nickel, which further increases resistance to chemical and atmospheric corrosion. two, says Von Kaenel. It doesn't have as much nickel as 304, but makes up for it in magnesium (which contributes to its corrosion-resistant nature). Both alloys have a high resistance to corrosion and nearly the same amount of chromium. Chromium is what makes stainless steel stainless by forming a protective layer of chromium oxide on the metal's surface. There are well over 150 differ- ent grades of stainless used in a number of industries but the most common in foodservice are 201, 301, 304, 316 and 430. Often referred to as 18/8 because of its composition—18 percent chromium and 8 percent nickel—304 is the grade of choice in E&S because of its durability and corrosion-resistant properties. "For as long as I've been in the indus- try, 304 has been the consultant's stain- less," says Von Kaenel, who still recalls when consultants would show up on the jobsite with a magnet in hand to make sure they were getting 304 stain- less—and not 430. "On the whole, our industry is very slow to accept change, so when 430 came into the marketplace, it was very controversial," he says. "While acceptable in several applications, it is susceptible to staining over a period of time and they were starting to have prob- lems with it in certain environments. Salt really affects the 400-series stainless and it will eventually turn it black." That's because type 430 is an iron-chro- mium alloy. It's also magnetic, "which doesn't make it bad," says Alderman, "just different." Stainless in the 400 series belong to the ferritic family. They contain little or no nickel, and are not as durable as aus- tenitic grades like 304 and 201—or as resistant to acids, bleach and improper care. But they do contain chromium and other corrosion-resistant properties in smaller amounts, which makes them a decent choice for mildly corrosive envi- ronments, according to Von Kaenel. "A lot of 430 is used in economical jobs," he says. "But if you're going to sell your cus- tomer something that's going to come in contact with a lot of acidic product, upgrade them to a 300-series-grade stain- less and tell them why. It costs more, but in the overall scheme of things, it's better." "Do This and Not That" It's also important to stress to the end user that just because their two-com- partment sink is made of stainless steel doesn't mean it won't stain, scratch or rust. "Essentially it's like anything else in your kitchen," says Alderman. "The qual- ity of your stainless is only as good as the quality of your care." Dealers can help by schooling their customers on the do's and don'ts, and according to Alderman, there's plenty of room for improvement. "The biggest cause of rust in a commercial kitchen is operator error and dealers need to do a better job educating their customers," he says. Different alloys resist corrosion to varying degrees but all are susceptible to mainstays found in a commercial kitchen. Blood from meat products, acidic foods, steel wool, saltwater, petroleum prod- ucts, and even a metal can left lingering on a tabletop (in a moist environment) can rust stainless steel over a period of time. As for missteps that often lead to callbacks, Alderman's top three are the improper use of bleach (times two), failure to thoroughly rinse product with clean water and completely dry, and the use of steel wool to clean, opposed to stainless wool pads. "Basically, they're like metal brushes," says Alderman, "and when you use one to clean items in the sink, little particles of steel break off and lodge themselves into microscopic parts of the sink. Over time, the steel rusts and leaves spots. No dealer should ever be selling any- thing except stainless wool, never steel wool or Brillo pads. And they should be explaining to their customers why they should be buying it." Bleach and other cleaning products warrant the same level of caution to stave off corrosion. The problem is the average restaurant employee often assumes more is better and fails to fol- low proper cleaning instructions. Costly offenses include ignoring recommend- ed mixing concentrations, neglecting to rinse with clean water after wiping down equipment and leaving bleach on the surface--with the intent to disinfect. "Regardless of whether it's a vertical