Miller Electric KC237900 manual Green Band, Thorium Alloyed Tungsten Red Band

Table 6-2. Tungsten Size Chart

Electrode Diameter		Amperage Range - Polarity - Gas Type
Pure Tungsten	DC-Argon Electrode	DC-Argon Electrode	AC-Argon Using	AC-Argon Balanced
(Green Band)	Negative/Straight Polarity	Positive/Reverse Polarity	High Frequency	Wave Using High Freq.
.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
2% Thorium Alloyed
Tungsten
(Red Band)
.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
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

*NOT RECOMMENDED

The figures listed are intended as a guide and are a composite of recommendations from American Welding Society (AWS) and electrode manufacturers.

S-0009/8-88

6-3. SPARK GAP ADJUSTMENT (Figure 6-3)	IMPORTANT: Spark gaps widen with normal operation.
	At regular inspections, check and maintain the spark air
It is necessary to readjust the spark gaps every three to	gap to ensure consistent welding results and com-
four months or when intermittent operation occurs. Nor-	pliance with FCC radiation regulations.
mal spark gap setting is 0.008 in. (0.203 mm).	IMPORTANT: Do not clean or dress points since the

High-frequency output varies with the spark gap setting. When a great amount of high frequency is necessary, the spark gaps can be adjusted to 0.010 in. (0.254 mm).

material at the tips is tungsten and impossible to file. The entire point should be replaced when the tungsten section has completely disappeared.

This, however, increases high-frequency radiation
which increases interference with communications	This unit is provided with a spark gap assembly located
equipment. It is suggested that a minimum spark gap	inside the unit in the lower right side (refer to Parts List
setting be used.	views). To adjust spark gaps, proceed as follows:

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