Which of the following is NOT a characteristic of Helium?

• A. Good for light gauge metal
• B. Non-reactive
• C. Colorless gas
• D. Low density

Answer: (A)

Helium’s shielding gas properties include being non-reactive, colorless, and very light in density. Its extremely high thermal conductivity means it adds more heat to the weld area and penetrates more deeply, which isn’t ideal for thin, light-gauge metal where you want to limit heat and avoid burn-through. That combination makes helium less suitable for light-gauge sections, even though the other traits—being inert, colorless, and low-density—are accurate. So the statement about being good for light gauge metal is not a characteristic of helium.