Easy Methods to Distinguish Between 304 and 201 Stainless Steel Sheets!

Simple methods to distinguish between 304 and 201 stainless steel sheets.

Due to its outstanding corrosion resistance, 304 stainless steel is frequently used as the inner layer in applications that require direct contact with water. On the other hand, 201 stainless steel, which has inferior corrosion resistance, is generally used for the outer layer of insulated water tanks. Despite being cheaper, some dishonest vendors may substitute 201 stainless steel for 304, leading to water tanks that corrode within 1-2 years, thus posing safety risks.

Here are straightforward ways to tell these two materials apart:

1. Specifications: The commonly used stainless steel sheets are mainly divided into 201 and 304, with the primary difference being their composition. 304 is superior in quality and more expensive, while 201 is less so. 304 is usually imported, while 201 is made locally.

2. 201 Composition: Comprising 17% Chromium, 4.5% Nickel, 6% Manganese, and Nitrogen, 201 is a nickel-saving type of steel and a replacement for 301 steel. It becomes magnetic after cold working and is used in railway vehicles.

3. 304 Composition: With 18% Chromium and 9% Nickel, 304 is the most widely used stainless and heat-resistant steel. It is utilized in food production equipment, chemical processing equipment, and nuclear energy applications.

4. Visual and Corrosion Characteristics: 201's higher manganese content gives it a bright, slightly dark appearance and makes it prone to rust. 304, with more chromium, has a matte finish and does not rust. The two types placed together show a clear difference. The primary difference is corrosion resistance: 201 has poor corrosion resistance and is significantly cheaper. Due to lower nickel content, 201's corrosion resistance is not as good as 304's.

5. Cost and Rust Resistance: The main difference between 201 and 304 lies in their nickel content. Although 304 is pricier, it guarantees rust-free use. (You can verify this using a stainless steel testing liquid.)

6. Rust Resistance Mechanism: Stainless steel avoids rust because of a protective chromium-rich oxide layer that forms on the surface. 201, being a high-manganese stainless steel, is harder and has higher carbon but lower nickel content than 304.

7. Composition Differences: The major differences between 201 and 304 stainless steel are in their carbon, manganese, nickel, and chromium content.