Choosing the Right Stainless Steel Grade

Did you know that there are five families of stainless steel? The most commonly used family is austenitic. This is due in large part to grades 304 and 316—among the most widely used across the world—falling within this family. In Texas, these grades are found in everything from food trucks to freight cars.

These grades of stainless steel exhibit:

• Excellent weldability

• Good formability

• Good market availability—and available in a wide range of dimensions, product forms and surface finishes

Here is a closer look at 304 and 316 stainless steel (as well as a few other commonly used grades within the austenitic family):

304

As the most widely used of all stainless steel grades, 304 is most notably present in industrial applications and kitchen equipment.

304 stainless steel is a heat-resistant grade, offering good corrosion resistance to many chemical corrodents, as well as industrial atmospheres. 304 stainless steel also exhibits good formability, meaning it can be readily welded by all common methods.

There is also 304L, which is an extra low carbon variation. This variation offers the same corrosion resistance as 304, but with slightly lower mechanical properties.

316

When it comes to 316 stainless steel, this grade is more resistant to corrosion and pitting than 304. It also offers higher strength at elevated temperatures compared with 304. Like 304 stainless steel, an extra low carbon variation of 316 is available, called 316L. This stainless steel grade helps avoid carbide precipitation due to welding.

You will find 316 stainless steel most commonly used in such applications as pumps, valves, textile and chemical equipment, pulp & paper and marine applications.

201

While Texas doesn’t experience many sub-zero temperatures, stainless steel 201 is the grade that could hold up well in these conditions. Unlike grades in the 300 series, 201 contains manganese and nitrogen in place of nickel. This grade is also considered to exhibit good mechanical and corrosion properties.

You can find 201 stainless steel in a variety of structural applications at ambient temperatures, as well as in truck trailers, railroad freight cars, coal handling and other transportation equipment where good corrosion resistance, strength and tolerance are necessary.

309

At the opposite end of the environmental temperature scale is stainless steel 309. Used in high-temperature applications, 309 stainless steel exhibits a high scale resistance and corrosion resistance superior to 304. This grade of stainless steel is exceptional when it comes to resisting sulfite liquids, nitric acid, nitric-sulfuric mixtures, acetic, citric and lactic acids.

301

When looking at those sinks inside a food truck on the streets of Texas, you may be looking at stainless steel grade 301. This grade exhibits low levels of nickel and chrome but high carbon content, which gives it an increased cold work-hardening range. This permits higher tensile strengths to be achieved.

In addition to sinks, stainless steel grade 301 can commonly be found in such applications as hose clamps and automobile moldings.