| Operations |
Electrode Size 1/32 in. |
Arc Current |
Minimum* Protective Shade |
| Shielded metal are welding |
Less than 3 |
Less than 60 |
7 |
| 3-5 |
60-160 |
8 |
| 5-8 |
160-250 |
10 |
| More than 8 |
250-550 |
11 |
| Gas metal are welding and flux cored arc welding |
|
Less than 60 |
7 |
| |
60-160 |
10 |
| |
160-250 |
10 |
| |
250-500 |
10 |
| Gas Tungsten arc welding |
|
Less than 50 |
8 |
| |
50-150 |
8 |
| |
150-500 |
10 |
| Air carbon |
(light) |
Less than 500 |
10 |
| Arc cutting |
(heavy) |
500-1000 |
11 |
| Plasma are welding |
|
Less than 20 |
6 |
| |
20-100 |
8 |
| |
100-400 |
10 |
| |
400-800 |
11 |
| Plasma arc cutting |
(light)** |
Less than 300 |
8 |
| (medium)** |
300-400 |
9 |
| (heavy)** |
400-800 |
10 |
| Torch brazing |
|
|
3 |
| Torch Soldering |
|
|
2 |
| Carbon arc welding |
|
|
14 |
Filter Lenses for Protection Against Radiant Energy
| Operations |
Plate thickness- in. |
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.
** These values apply where the actual arc is clearly seen. Experience has shown that lighter filters may be used when the arc is hidden by the workplace.
