Stellite 6 vs Stellite 21 – What’s the Difference?

Stellite alloys have been used in a variety of industrial applications for decades. Their unique properties make them an ideal fit for critical corrosion and wear resistance areas. The two most commonly used stellite alloys are Stellite 6 and Stellite 21. While both alloys may sound similar, there are some significant differences. This blog post will explore the key differences between Stellite 6 and Stellite 21 and their applications.

Difference between Stellite 6 and Stellite 21

Chemical Composition

One of the most fundamental differences between Stellite 6 and Stellite 21 is their chemical composition. Stellite 6 is primarily composed of a cobalt-chromium alloy with carbon, tungsten, and molybdenum additions. Stellite 21 has more cobalt and chromium than Stellite 6, with additional components, including nickel and tungsten. The higher cobalt and chromium content in Stellite 21 ensures superior corrosion resistance properties than Stellite 6.

Mechanical Properties

The mechanical properties of Stellite 6 and Stellite 21 differ greatly. Stellite 6 has high wear and abrasion resistance, making it an ideal choice for hard-facing oil and gas, mining, and agriculture applications. It also has excellent resistance to thermal shocks and deformations under high heat conditions. In contrast, Stellite 21 has excellent corrosion resistance properties, making it an ideal choice for areas with chemical and corrosive substances. It also has high toughness and good weldability.


Stellite 6 and 21 are used in various applications because of their unique properties. Stellite 6 is commonly used for hard-facing applications because of its wear and abrasion-resistant properties. It is also used in valve seats, steam turbines, and dental equipment. On the other hand, Stellite 21 is commonly used in hydrochloric and sulfuric acid service environments and refining industries. It is also used when resistance to high temperatures and corrosion is critical, such as in heat exchangers and valves.


Regarding cost, there is a significant difference between Stellite 6 and Stellite 21. Stellite 6 is more affordable than Stellite 21 because of its lower cobalt and chromium content. However, its affordability does not take away from its quality. Stellite 6 is an excellent choice for areas where wear resistance is critical. For More information visit marketsmartb2b


In conclusion, Stellite 6 and Stellite 21 have unique properties that make them ideal for various industrial applications. Stellite 6 is commonly used for hard-facing applications, while Stellite 21 is used in areas requiring corrosion resistance and high temperatures. While they may seem similar, it is essential to understand their differences to ensure the best fit for your application. Regardless of which is used, both alloys are reliable and valuable solutions to industrial wear and corrosion problems.

Leave a Reply

Your email address will not be published. Required fields are marked *