SECTION 7 – SELECTING AND PREPARING
TUNGSTEN ELECTRODE
gtaw2 7/97
NOTE
For additional information, see your distributor for a handbook on the Gas Tungsten Arc Welding (GTAW) process. Wear clean gloves to prevent contamination of tungsten electrode.
7-1. Selecting Tungsten Electrode
| Amperage Range - Gas Type♦ - Polarity | |
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Electrode Diameter | DC – Argon – Electrode Negative/Straight | DC – Argon – Electrode Positive/Reverse |
| Polarity | Polarity |
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2% Thorium Alloyed Tungsten (Red |
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Band) |
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.010” | Up to 25 | * |
.020” | * | |
.040” | * | |
1/16” | ||
3/32” | ||
1/8” | ||
5/32” | ||
3/16” | ||
1/4” | ||
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♦Typical argon shielding gas flow rates are 15 to 35 cfh (cubic feet per hour) – 7 to 16.5 lpm (liters per minute). *Not Recommended.
The figures listed are intended as a guide and are a composite of recommendations from American Welding Society (AWS) and electrode manufacturers.
7-2. Safety Information About Tungsten
Y Grinding the tungsten elec-
| trode produces dust and fly- | |||
| ing sparks which can cause | |||
1 | injury and start fires. Use lo- | |||
cal exhaust (forced ventila- | ||||
| ||||
| tion) at the grinder or wear an | |||
| approved respirator. Read | |||
| MSDS for safety information. | |||
| Consider | using | tungsten | |
| containing ceria, | lanthana, | ||
| or yttria | instead of thoria. | ||
| Grinding dust from thoriated | |||
2 | electrodes contains | |||
el radioactive | material. | |||
| ||||
| Properly dispose of grinder | |||
| dust in an environmentally | |||
| safe way. Wear proper face, | |||
| hand, and body protection. | |||
| Keep flammables away. | |||
1 | Tungsten Electrode With | |||
| Balled End |
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2 | Pointed Tungsten Electrode |
Ref.