The solar flux used on stainless steel is Type B.

• A. Type 202
• B. Type 16
• C. Type B
• D. Type A

Answer: (C)

Flux choices tell you which metals they’re formulated to protect and how they help the joint form properly during heating. For stainless steel, you need a flux that prevents oxidation and promotes good wetting of the base metal by the filler. Type B flux is specifically formulated for stainless steel, so using it on stainless ensures the surface stays protected and the joint wets well, which is why it’s the correct choice. Using a flux meant for other metals wouldn’t provide the same protection or compatibility, potentially leading to poor bonding or contamination. In short, Type B is the flux designed for stainless steel applications, making it the right pick here.