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

 

 

 

Electrode Diameter

DC – Argon – Electrode Negative/Straight

DC – Argon – Electrode Positive/Reverse

 

Polarity

Polarity

 

 

 

2% Thorium Alloyed Tungsten (Red

 

 

Band)

 

 

 

 

 

.010”

Up to 25

*

.020”

15-40

*

.040”

25-85

*

1/16”

50-160

10-20

3/32”

135-235

15-30

1/8”

250-400

25-40

5/32”

400-500

40-55

3/16”

500-750

55-80

1/4”

750-1000

80-125

 

 

 

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 low-lev-

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

 

 

2

Pointed Tungsten Electrode

Ref. S-0161

OM-355 Page 22

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Image 26
Hobart 180 SD Selecting and Preparing Tungsten Electrode, Selecting Tungsten Electrode, Safety Information About Tungsten