Which shade number is used for gas welding light, up to 1/8 inch?

Which shade number is used for gas welding light, up to 1/8 inch?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (C)

Gas welding uses a flame, which is bright but not as intense as an electric arc, so the filter can be lighter to keep good visibility while still protecting the eyes. For light gas-welding of very thin stock, the appropriate shade is four. This shade strikes a balance: it blocks enough UV and IR radiation from the flame while letting you clearly see the weld pool and joint. If the material were thicker or the flame hotter, a darker shade would be needed to prevent eye injury. Lighter options would let too much radiation through and aren’t sufficient protection for a gas flame.

Gas welding uses a flame, which is bright but not as intense as an electric arc, so the filter can be lighter to keep good visibility while still protecting the eyes. For light gas-welding of very thin stock, the appropriate shade is four. This shade strikes a balance: it blocks enough UV and IR radiation from the flame while letting you clearly see the weld pool and joint. If the material were thicker or the flame hotter, a darker shade would be needed to prevent eye injury. Lighter options would let too much radiation through and aren’t sufficient protection for a gas flame.