Which shade number is used for gas welding heavy, over 1/2 inch?

• A. 5
• B. 6
• C. 7
• D. 8

Answer: (B)

When selecting eye protection for gas welding, the shade you choose depends on the amount of radiant energy you’re exposed to, which increases with thicker metal. Gas welding has less radiant output than arc welding, but as the material thickness grows (over 1/2 inch), you still need a darker lens to protect your eyes.

For heavy gas welding over half an inch, a shade 6 provides a good balance: it darkens enough to shield the eyes from the increased heat and glare while still letting you see well enough to work safely. Lighter work would use a lighter shade, but for this thickness, shade 6 is the standard choice. Higher numbers like 7 or 8 are typically reserved for higher-intensity arc welding and would be unnecessarily dark for gas welding.