What shade filter lenses are recommended to protect against UV light during torch brazing?

The recommended shade filter lens for protection against UV light during torch brazing is typically a shade 4. This shade provides a suitable balance of visibility and eye protection. During brazing, a significant amount of UV radiation is emitted from the molten metal, which can be harmful to the eyes. Shade 4 filters effectively block harmful UV rays while still allowing the user to see the work clearly enough to manage the brazing process effectively.

Shader lenses that are too dark, such as shade 6, can impede visibility and make it difficult for the operator to accurately monitor the brazing process. On the other hand, lighter shades, like shade 2 or shade 5, may not provide adequate protection against the intense UV light generated during the operation, risking eye damage. Thus, shade 4 is the ideal choice for the safety and effectiveness needed in torch brazing operations.