Select proper size tungsten (see section 8-1, 1. selecting tungsten electrode – Miller Electric HF-251D-1 Manuel d'utilisation
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OM-611 Page 24
SECTION 8 − SELECTING AND PREPARING TUNGSTEN
ELECTRODE FOR DC OR AC WELDING
ac/dc_gtaw 2/2004
Y
Whenever possible and practical, use DC weld output instead of AC weld output.
8-1.
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.