OM-350 Page 30
SECTION 7 – SELECTING AND PREPARING TUNGSTEN
ELECTRODE FOR DC OR AC WELDING
ac/dc_gtaw 2/2000
Y Whenever possible and practical, use DC weld output instead of AC weld output.
7-1. Selecting Tungsten Electrode (Wear Clean gloves To Prevent Contamination Of Tungsten)
Amperage Range - Gas Type♦ - Polarity
Electrode Diameter DC – Argon – Electrode
Negative/Straight Po-
larity
DC – Argon – Elec-
trode Positive/Rev-
erse Polarity
AC – Argon AC – Argon –
Balanced Wave
2% Ceria (Orange Band), 1.5% Lan-
thanum (Gray Band), Or 2% Thorium
(Red Band) Alloy Tungstens
.010” Up to 25 * Up to 20 Up to 15
.020” 15-40 * 15-35 5-20
.040” 25-85 * 20-80 20-60
1/16” 50-160 10-20 50-150 60-120
3/32” 135-235 15-30 130-250 100-180
1/8” 250-400 25-40 225-360 160-250
5/32” 400-500 40-55 300-450 200-320
3/16” 500-750 55-80 400-500 290-390
1/4” 750-1000 80-125 600-800 340-525
Pure Tungsten
(Green Band)
.010” Up to 15 * Up to 15 Up to 10
.020” 5-20 * 5-20 10-20
.040” 15-80 * 10-60 20-30
1/16” 70-150 10-20 50-100 30-80
3/32” 125-225 15-30 100-160 60-130
1/8” 225-360 25-40 150-210 100-180
5/32” 360-450 40-55 200-275 160-240
3/16” 450-720 55-80 250-350 190-300
1/4” 720-950 80-125 325-450 250-400
Zirconium Alloyed Tungsten (Brown
Band)
.010” * * Up to 20 Up to 15
.020” * * 15-35 5-20
.040” * * 20-80 20-60
1/16” * * 50-150 60-120
3/32” * * 130-250 100-180
1/8” * * 225-360 160-250
5/32” * * 300-450 200-320
3/16” * * 400-550 290-390
1/4” * * 600-800 340-525
♦Typical argon shielding gas flow rates are 15 to 35 cfh (cubic feet per hour). *Not Recommended.
Figures listed are a guide and are a composite of recommendations from American Welding Society (AWS) and electrode manufacturers.
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