Miller Electric HF-251D-1, HF-251-2 manual Amperage Range Gas Type Polarity, AC − Argon AC − Argon

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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	DC − Argon − Elec-		AC − Argon	AC − Argon −
	Negative/Straight Po-	trode Positive/Rev-			Balanced Wave
	larity	erse Polarity
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. OM-611 Page 24