What is the best quality of stainless steel?

What's the difference between the different grades of stainless steel (304, 430, 220, etc.)? What do the different numbers mean (18/8, 18/10, 18/0, etc.)? We often get these questions here at MightyNest and hope this post helps answer those questions.

The "grade" of stainless steel refers to its quality, durability and temperature resistance. The numbers (18/8, 18/10, etc.) are the composition of the stainless steel and refer to the amount of chromium and nickel (respectively) in the product.

So, what do the numbers mean?

18/8 and 18/10: These are the two most common grades of stainless steel used for food preparation and dining, also known as Type 304 (304 Grade) and are part of the 300 series. The first number,18, refers to the amount of chromium present and the second represents the amount of nickel.  For example, 18/8 stainless steel is comprised of 18% chromium and 8% nickel.  

304 grade stainless steel is also comprised of no more than 0.8% carbon and at least 50% iron. The chromium binds oxygen to the surface of the product to protect the iron from oxidation (rust). Nickel also enhances the corrosion resistance of stainless steel.  Therefore, the higher the nickel content, the more resistant the stainless steel is to corrosion. 

18/0 - Contains a negligible amount of nickel (0.75%) and therefore has a reduced corrosion resistance (is more likely to rust than 18/8 or 18/10 but still high quality) 18/0 is also referred to as Type 430, is part  of the 400 series and, unlike 300 series stainless steel, is magnetic.

200 series: You may often find stainless steel food containers made from 200 series stainless steel.  These are typically less expensive than 304 grade as manufacturers essentially substitute manganese for nickel.  Although food safe, they are not as resistant to corrosion and not as high quality as 304 grade.  

What about stainless steel flatware?

When it comes to flatware, people often assume that 18/10 is heavier in weight. Actually, there is no difference between 18/8 and 18/10 flatware when it comes to weight.  The additional nickel in 18/10 flatware makes it a bit sturdier (meaning the tines of a fork are slightly more difficult to bend back and forth). The additional nickel also lends itself to a shinier surface.

What about stainless steel cookware?

Stainless steel is a great alternative to teflon coated aluminum cookware.   However, on the stove or cook top, stainless steel alone doesn't provide optimal heating which is why pots and pans are generally made of tri-ply construction.  In the case of a stainless steel frying pan, an aluminum core is sandwiched between two layers of 18/10 stainless steel allowing heat to distribute evenly across the pan. In these pans the aluminum does not react or come into contact with food at all.

Is stainless steel safe?

Stainless steel is one of the most common materials found in kitchens today.  It's used in everything from appliances to cookware, dishware, flatware and utensils because it is durable, easy to sanitize and corrosion resistant to various acids found in meats, milk, fruits and vegetables.  Most importantly though, stainless steel is a safe option when it comes to use with food and beverage, as there are no chemicals that can migrate into your food from these products.

We believe that stainless steel, glass, cast iron, wood, ceramics with lead-free glaze and bamboo are the safest materials to use in the kitchen. MightyNest offers a wide variety of stainless steel products including 18/8 water bottles, bowls, food storage containers and dishware as well as 18/10 pots and pans, bakeware, wine glasses and kids utensils.

What other questions do you have about stainless steel?

At first glance, in comparing 304 vs 316 stainless steel, the lines between the two grades may seem fine. Each has more properties in common than not—both have very good corrosion and heat resistance, strength, and excellent welding and forming properties. In fact, 304 and 316 are two of the most popular grades of stainless steel. It’s no wonder—like all stainless steel grades—the material is easy to fabricate, clean, and maintain, and is exceptionally durable, environmentally friendly, and aesthetically pleasing.

Such material properties make stainless steel a top choice in the fabrication of parts and components for numerous applications and products. Yet the term stainless steel can be somewhat confusing. Mainly because stainless steel does not specifically define a particular type of material, but broadly defines a class of iron-based alloys that give steel corrosion-resistant properties. In essence, stainless steels are low-carbon steel that consists of a minimum of at least 10.5% chromium, which gives the material its defining characteristic and corrosion resistance. The steel can then be combined with other alloying elements such as nickel, manganese, silicon, nitrogen, titanium, molybdenum and more. However, it is the amount and variety of alloying elements used that determine the grade and type of stainless steel. There are over 100 grades of stainless steel, and 304 and 316 are but two of them.

What further differentiates 304 and 316 grades are their classification as austenitic, a type of stainless steel which refers to a specific category of stainless steel derived from the material’s crystalline microstructure. Austenitic steels—those 200 and 300 series as categorized by the AISI/SAE grade system—are the most commonly used type of stainless steels. They have relatively low levels of carbon and high levels of nickel and chromium—the latter provides a protective oxide layer to the surface of the material. The material is non-magnetic, with exceptional heat and corrosion resistance, and formability and strength. Austenitic 304 and 316 stainless steels are well regarded for their hygienic properties and are considered food, surgical or medical-grade stainless steels.

Key Difference
Nonetheless, as subtle as they may be, there are differences between the two 304 and 316 grades, with the one key difference that distinguishes one grade from another being the addition of molybdenum to the chemical composition of grade 316. Molybdenum enhances the material’s corrosion resistance, especially for applications in saline or chloride-exposed environments, but the addition of molybdenum to the chemical composition of 316, as well as the increase in nickel, make 316 more expensive per ounce of material than 304, with some estimates ranging upwards of 40% more in cost.

Applications

Grade 304
Also referred to as “18/8” in reference to its 18% chromium/8% nickel chemical composition, grade 304 is considered the most versatile and widely used of any grade of stainless steel. Its many favorable characteristics and austenitic structure make it an ideal grade for use in a wide array of industrial parts and components, chief among these are springs, nuts, bolts and screws. Far more than that, due to its innate hygienic properties, 304 stainless steel is used in the fabrication of food processing equipment, sinks and splashbacks, kitchen equipment like cutlery, flatware, and saucepans, sanitary ware, troughs, and tubing, as well as for brewery, dairy, food and pharmaceutical production equipment. Because of its strength and aesthetic appeal, and heat and corrosion resistance, 304 is also used in the fabrication of automobile parts, architectural paneling, railing and trim, heat exchangers, and parts for various marine applications.

Grade 316
Grade 316 stainless steel has a chemical composition of 16% chromium, 10% nickel, 2% molybdenum, and .08% carbon, and is used to fabricate parts, components, and products in applications that require exceptionally high corrosion resistance. This would include chemical processing equipment, tanks, and evaporators, valve and pump parts, marine parts, outdoor electrical enclosures, exhaust manifolds and engine parts, and heat exchangers. The hygienic properties of 316 make it ideal for use in pharmaceutical, surgical and medical applications—this includes hypodermic needles, needle caps or guards, surgical instruments, dental implants, and more.

Both 304 and 316 grades stainless steel offer very good corrosion resistance and provide the strength, durability, and heat resistance that make the materials a top choice in the fabrication of parts in components for a wide variety of products in numerous industries. Though more costly, 316 stainless steel gets an edge in applications that require a higher degree of corrosion resistance. For more information, contact James Spring and Wire Company.