Table I-1-Filter Lenses for Protection Against Radiant Energy
Operations | Electrode size 1/32 in | Arc current | Minimum * protective shade |
Shielded metal arc welding | Less than 3 3-5 5-8 More than 8 | Less than 60 60-160 160-250 250-550 | 7 8 10 11 |
Gas metal arc welding and flux cored arc welding | Less than 60 60-160 160-250 250-500 | 7 10 10 10 | |
Gas Tungsten arc welding | Less than 50 50-150 150-500 | 8 8 10 | |
Air carbon | (Light) | Less than 500 | 10 |
Arc cutting | (Heavy) | 500-1000 | 11 |
Plasma arc welding | Less than 20 20-100 100-400 400-800 | 6 8 10 11 | |
Plasma arc cutting | (light) ** (medium) ** (heavy) ** | Less than 300 300-400 400-800 | 8 9 10 |
Torch brazing | 3 | ||
Torch soldering | 2 | ||
Carbon arc welding | 14 |
** These values apply where the actual arc is clearly seen. Lighter filters may be used when the arc is hidden by the workpiece.
Filter Lenses for Protection Against Radiant Energy
Operations | Plate thickness-inches | Plate thickness-mm | Minimum * protective shade |
Gas Welding: | |||
Light | Under 1/8 | Under 3.2 | 4 |
Medium | 1/8 to 1/2 | 3.2 to 12.7 | 5 |
Heavy | Over 1/2 | Over 12.7 | 6 |
Oxygen cutting: | |||
Light | Under 1 | Under 25 | 3 |
Medium | 1 to 6 | 25 to 150 | 4 |
Heavy | Over 6 | Over 150 | 5 |
* As a rule of thumb, start with a shade that is too dark to see the weld zone. Then go to a lighter shade which gives sufficient view of the weld zone without going below the minimum. In oxyfuel gas welding or cutting where the torch produces a high yellow light, it is desirable to use a filter lens that absorbs the yellow or sodium line in the visible light of the (spectrum) operation.
29 C.F.R. §1915.153