201 Vs 304 Stainless Steel - What Is The Difference?
It’s well-known that SAE 304 stainless steel is the most versatile stainless steel used across various industries, in addition to its “nearest cousin,” SAE 316 stainless steel. However, the high nickel content within SAE 304 alloy makes this stainless steel type quite pricey, so engineers sometimes resort to a more affordable replacement: SAE 201 stainless steel.
In this guide, we’ll discuss stainless steel 201 vs stainless steel 304, their differences, similarities, and their applications.
What’s the Difference Between SAE 201 and SAE 304 Stainless Steel?
Besides the difference in chemical composition, which we’ll discuss shortly, there are some barely noticeable visual differences between the two types of stainless steel. Namely, due to generally lower chromium content and high manganese content, SAE 201 appears slightly darker compared to SAE 304.
However, as stated above, these differences are barely noticeable, and you’d have to place both stainless steel materials next to one another for them to become apparent.
Chemical Composition
Both grades of stainless steel have relatively high chromium and nickel content. However, they belong to entirely different alloy groups, which is what sets them apart. SAE 304 is an austenitic stainless steel that has between 18% and 20% chromium, 0.08% carbon, and 8%-10% nickel. This type of steel belongs to chromium-nickel alloys.
However, SAE 201 stainless steel belongs to a chromium-manganese-nickel group, which denotes a relatively high manganese content and relatively low nickel content. SAE 201 is an austenitic stainless settle with a relatively high carbon content of 0.15% and a relatively low nickel content of 3.5% to 5.5%. It has approximately 16-18% chromium and 5.5 to 7.5% manganese.
Corrosion Resistance
Both SAE 304 and SAE 201 gain their corrosion resistance from their chromium and nickel content. However, SAE 304 has a higher percentage of both alloying elements within the allow, which provide the alloy with excellent corrosion resistance.
Unfortunately, SAE 201 has fewer of these alloying elements, which makes its corrosion resistance subpar to that of SAE 304. The latter is mostly used in hygienic applications, like food-grade containers and stainless steel water bottles, due to its good corrosion resistance.
However, some insulated water bottle manufacturers use SAE 201 for their stainless steel products, which is an inadequate application, and perhaps even a hazardous misuse of materials.
Physical Properties
SAE 201 stainless steel is relatively more rigid than the SAE 304, which has considerably better mechanical properties and fatigue resistance than SAE 201. However, the appealing factor of SAE 201 is its affordable price tag, good performance in cold weather, and indoor applications, such as door knobs or workholding elements such as jigs and fixtures.
Summary
The differences between SAE 304 and 201 become apparent differently depending on the application. In some instances, the more affordable SAE 201 seems reasonable, while it can barely compete against SAE 304 in others.
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