What is the purpose of a gas lens in the TIG nozzle?

• A. To reduce shielding gas consumption
• B. To improve gas flow pattern
• C. To increase arc temperature
• D. To adjust electrode polarity

Answer: (B)

The gas lens is there to shape and stabilize the shielding gas around the weld. By guiding the gas through a fine screen structure, it converts the gas flow from a rough jet into a more laminar, collimated stream. That reduces turbulence and air entrainment, providing a more uniform shield over the weld pool. With this steadier shield, the weld is better protected from contamination and the arc tends to stay steadier, which improves bead quality and reduces defects. It doesn’t change the arc temperature or electrode polarity; its main job is the flow pattern of the shielding gas.