The lens shade for SMAW work is most commonly #10.

• A. #9
• B. #10
• C. #11
• D. #50

Answer: (D)

Choosing the right lens shade is about balancing eye protection with the ability to see the weld clearly. The arc in SMAW emits intense light and harmful rays, so a filter is needed to protect the eyes while you still can see the puddle and bead to control the weld properly.

For typical SMAW work, a mid-range shade around 10 is the standard choice. It blocks enough ultraviolet and infrared and reduces glare, yet still lets you see the weld pool well enough to position and travel smoothly. Shade numbers higher than this (like 11 or 12) can protect even more, but they make it harder to see the weld details, which can slow you down or lead to less precise welds. Shade numbers lower than this (like 9) may not provide sufficient protection for common SMAW currents.

A shade as dark as 50 would be far too dark to see the weld at all, making welding impractical. So the most commonly used shade for SMAW is around #10, giving a good balance between protection and visibility.