Stainless steel is a type of steel that does not corrode easily, making it ideal for many applications where it can be exposed to harsh environments and corrosive materials including hot and cold temperatures and liquids. As a result, stainless steel is often referred to as “the corrosion resistant metal.” Stainless steel is also known for its strength, as it is less likely to be damaged or weakened by heavy loads.
Due to its durability and strength, stainless steel is used in a wide variety of applications, from appliances and tools, to utensils, piping, and other forms of infrastructure. Despite its many uses, stainless steel is a versatile material and comes in many different grades and forms, depending on the specific application it is being used for.
One way to categorize different grades of stainless steel is to think of them as subdivisions along the spectrum of steel alloys. The most basic stainless steel alloys that exist are known as the 2XX series and comprise of alloys such as 201, 202, 203, and so on. The 200 series alloys are generally non-magnetic and are ideal for applications where corrosion resistance is needed but hardness or strength is not necessary. For example, kitchenware, or components in water heaters, plumbing fixtures, and other machine parts often use the 200 series of alloys.
As we move to the 300 series, the alloys become magnetic and are generally considered more corrosion-resistant than the 200 series. The 300 series alloys are almost always austenitic and can contain 18% chromium and 8% or 10% nickel. These alloys are popularly used in oil and gas pipelines, kitchenware, and car parts, as well as many other general-purpose engineering applications.
The 400 series of stainless steel alloys contain extra chromium and carbon compared to the 300 series, allowing them to be both magnetic and formable, as well as resist heat better than the 300 series. The 400 series is great for applications such as springs and springs, fasteners, and utensils, and may also be used in some engineering applications.
The 500 series alloys contain more nickel and molybdenum than the 400 series, making them even more resistant to corrosion and heat. These alloys are often used in the petrochemical industry and for newer applications such as offshore drilling and nuclear power.
Finally, the 600 series includes alloys that feature additional elements such as nitrogen, copper, and silicon. These alloys are known for their superior corrosion-resistant properties and are used in food and medical production, in certain construction applications, as well as various chemical and industrial processes.
All of these stainless steel alloys have their own specific grade numbers corresponding to them, many of which are listed in the following table. The grade numbers are usually denoted by an “X” (such as 304X or 316X) or a “TP” (such as 304TP or 316TP) where the “X” or “TP” refers to the type of grade the alloy is. Knowing which grade of stainless steel you need is important for selecting the right type of material for your project.
