Mixing brass and stainless-steel fittings is not very common and shouldn't be overlooked because contamination and other problems can result in poor compatibility. Understanding how brass and stainless-steel varieties complement one another is crucial, as certain combinations do not mix well. For example, galvanic corrosion will occur in a system if the incorrect types are combined.
The metals should be listed on the anodic index with no more than a .15V to .25V difference between them. Since brass and 410 stainless steel are seven metals apart, they can rust. On the other hand, brass and 301, 304 and 310 stainless steels are only two metals apart, making it possible to link them safely with little chance of galvanic corrosion. This is why it is essential to know the types of brass and stainless steel when mixing. Though stainless steel 304 has a higher melting point, stainless 316 has a superior resistance to chemicals and salt compared to 304. That’s why 316 stainless steel is the most common grade in hydraulic and instrumentation fittings, especially in applications with chlorinated solutions or exposure to salt. 
When looking at the types of brass and stainless steel, ask yourself these questions:
Do I need corrosion resistance?
Due to their exceptional corrosion resistance, including a variety of chemicals, fluids, slurries and outer atmospheres, brass fittings are recommended for applications with highly corrosive conditions.
Do I need temperature resistance?
Both brass and stainless steel can withstand high temperatures for their specific applications. However, most stainless-steel fittings withstand higher temperatures of up to 1200°F, where brass is only rated to 400°F.
Do I need to be concerned with cost?
The cost difference is not significant between brass and stainless-steel fittings, although depending on the fitting type, brass can be less expensive. So, you could save yourself some money by blending brass and stainless-steel fittings when applicable.
In conclusion, both materials can be great options. However, understanding the different types of stainless steel and brass that work well together is essential. Using the wrong components might lead to contamination and other issues. To learn more about the types of fittings (carbon steel, stainless steel and brass), visit our blog post on stainless steel and brass fittings compatibility.
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