18-8 vs 303 Stainless Steel – What’s the Difference?

18-8 and 303 stainless steel are two commonly used grades that often raise questions about their differences. In this article, we aim to provide a detailed comparison between 18-8 vs 303 stainless steel, discussing their composition, properties, applications, and other relevant aspects.

18-8 vs 303 Stainless Steel – What’s the Difference?

18-8 vs 303 Stainless Steel – 1. Composition

18-8 stainless steel, also known as Type 304, is the most widely used stainless steel grade. It gets its name from its composition, which includes 18% chromium and 8% nickel. This chromium-nickel combination gives 18-8 stainless steel its excellent corrosion resistance, ductility, and weldability.

On the other hand, 303 stainless steel is a modified version of 18-8 stainless steel. It contains the same 18% chromium but has a reduced nickel content of only 8-10%. To compensate for the reduced nickel content, 303 stainless steel is alloyed with sulfur, which increases its machinability. The sulfur content also gives 303 stainless steel a free-machining characteristic, making it suitable for automatic screw machine operations.

18-8 vs 303 Stainless Steel – 2. Properties

18-8 stainless steel, due to its higher nickel content, exhibits better corrosion resistance than 303 stainless steel. It is resistant to corrosion from most oxidizing acids and can withstand exposure to chloride-containing environments without experiencing stress corrosion cracking.

303 stainless steel, on the other hand, while less corrosion-resistant than 18-8, still offers good corrosion resistance in many applications. Its sulfur content makes it easier to machine, but it also reduces its ductility and weldability compared to 18-8 stainless steel.

18-8 vs 303 Stainless Steel – 3. Applications

The differences in composition and properties of 18-8 and 303 stainless steel lead to different applications for each grade.

18-8 stainless steel is widely used in applications that require excellent corrosion resistance, such as kitchen appliances, surgical instruments, and architectural components. Its good weldability and ductility also make it suitable for complex fabrications and welding operations.

303 stainless steel, on the other hand, is commonly used in applications where machinability is a key requirement. It is often used in the manufacturing of fasteners, screws, and other threaded components due to its free-machining characteristic. It is also used in some corrosive environments, but its corrosion resistance is not as robust as that of 18-8 stainless steel.

18-8 vs 303 Stainless Steel – 4. Cost

The cost of 18-8 and 303 stainless steel can vary depending on various factors such as alloy content, production processes, and market demand. Generally speaking, 18-8 stainless steel is more widely used and produced, which can lead to lower costs compared to 303 stainless steel. However, the specific cost difference can vary depending on the specific application and market conditions.

Conclusion

In summary, 18-8 and 303 stainless steel differ in their composition, properties, and applications. 18-8 stainless steel, with its higher nickel content, offers excellent corrosion resistance, ductility, and weldability, making it suitable for a wide range of applications. On the other hand, 303 stainless steel, with its sulfur addition, provides good corrosion resistance and improved machinability, making it ideal for applications where machinability is a key requirement.

Thank you for reading our article and we hope it can help you to have a better understanding of the differences between 18-8 vs 303 Stainless Steel. If you are looking for 18-8 and 303 Stainless Steel suppliers online, we would advise you to contact Sino Stainless Steel.

As a leading supplier of stainless steel products from Shanghai, China, Sino Stainless Steel provides customers with high-quality stainless steel products such as stainless steel tubes, stainless steel pipes, stainless steel strips, stainless steel coils, stainless steel plates, stainless steel sheets, and stainless steel bars.