A D V A N C E D M A T E R I A L S & P R O C E S S E S | O C T O B E R 2 0 2 2 2 5 called austenite; thus, the term austenitic steel is sometimes used. Because of the amounts of nickel, this austinite crystal is maintained at room temperature, allowing it to be formed like a blacksmith does with hot steel. Austinite is also a non-magnetic crystal structure, and thus the use of a magnet test to differentiate 300 series from 400 series stainless. Recently, 316 stainless has been marketed as the best quality (and expensive) flatware. 316 stainless is 304 stainless with 2% expensive molybdenum designed for saltwater usage and chlorinated pools. It has super corrosion, stain resistance, higher hardness, and scratch resistance, but it is overkill for general dining flatware, and the cost cannot be justified. With one exception, 316 has the suitable properties for dishwasher usage. It always holds up and tolerates all commercial detergents. Unfortunately, there are many falsely advertised 316 sets, and there’s no way to distinguish them; it’s best to stick to well-known manufacturers. The 300 series stainless is expensive with the high cost of nickel, and metallurgists look for ways to reduce nickel content. There are other flatware stainless steel-grade options, such as the 400 stainless series, to consider. These lower-cost grades contain no nickel with two chromium contents, 18/0 and 13/0. They are known as restaurant grades and are prevalent in a daily home setting. However, highly polished forged 18/0 is becoming very popular in many settings. These lower-cost flatware stainless steels have no nickel and chromium levels of 18% (type 430) or 13% (type 420). The 400 series, lacking nickel, has a different crystal structure than the austenite of the 300 series, making them harder and magnetic. 400 stainless steels also contain higher carbon and manganese to allow the hardening of a knife blade. 400 stainless can be hardened with a crystal structure of martensite via heat treatment for cutting edges, and 18/0 is particularly suited for steak knives and low-quality cutting applications. The 400 series are magnetic steels versus non-magnetic of the higher stain resistant 300 series, so a simple magnet can help you distinguish it. Note that high carbon 400 grades such as 440 are used for chef and high-quality cutting knives. These higher carbon grades of the 400 series are in a different metallurgical world from those of flatware. The 18/0 is known metallurgically as grade 430 steel, and 13/0 is 420 steel. The cheapest flatware option is one of 13/0 (420 series), which contains no nickel and less chromium, reducing the weight and cost. Grade 13/0 lacks stain resistance in the long run, and 13/0 flatware is vulnerable to some corrosion (rust) and unlikely to keep its shine for a very long time and the author does not recommend it. When choosing the lower-cost 400 series for flatware, use 18/0. Forged stainless 18/0 makes good quality but requires more care and maintenance. In a world of steadily increasing nickel prices, 18/0 will grow in popularity. Understand the tradeoff. The 18% chromium content imparts good corrosion resistance to stainless steel, but it is not stain-resistant without nickel. For casual or high-volume events/restaurants, choosing 18/0 flatware will work well with its soft sheen and economic value. Flatware Code %chromium/%nickel Stainless type Properties Characteristics Notes 18/10 austenitic stainless 300 series 305 Non-magnetic; best corrosion and stain resistance; soft High luster Not hardenable for cutting edge Premium tableware High cost 18/8 austenitic stainless 300 series 304 Non-magnetic; corrosion and stain resistance; soft Shiny luster Not hardenable for cutting edge Excellent tableware High cost 316 austenitic stainless 18/8 plus 2%molybdenum 316 Non-magnetic: overkill for flatware applications It offers the potential to use the dishwasher Super corrosion resistant Hardest of 300 series 304 grade with 2%molybdenum High cost 18/0 martensitic stainless 400 series 430 Magnetic; corrosion resistant, and some stain resistance It can be hardened for cutting Higher carbon levels Dinner; kitchen and chef knives 13/0 martensitic stainless 400 series 420 Magnetic; fair corrosion resistance – no long-term stain resistance It can be hardened for cutting Higher carbon levels Can rust if not thoroughly dried Dinner; kitchen and chef knives Lowest cost flatware 200 series Cr-Mn steel Often mis- labeled “300 stainless” Non-magnetic; good corrosion and stain resistance better than 400 series Not hardenable for cutting edge Manganese used to reduce nickel It is usually stamped into thinner gauge flatware Good restaurant service TABLE 1 — METALLURGICAL DESCRIPTION OF COMMON TABLEWARE
RkJQdWJsaXNoZXIy MTYyMzk3NQ==