If you plan to weld with a particular diameter electrode, you need to know its operating range (basically, smaller electrodes carry less current, larger electrodes carry more current). The following chart suggests operating ranges for common Stick, wire, TIG and carbon arc gouging electrodes. This helps you determine which electrode sizes you can use with a particular machine.

Amperage for Stick Electrodes
Stick diameter and type	3/32"	1/8"	5/32"	3/16"	1/4"
6010, 6011	40-85	75-125	110-165	140-210	210-315
6013	40-90	80-130	105-180	150-230	250-350
7018	60-100	110-165	150-220	200-275	320-400

Amperage and Voltage for Wire Electrodes — Part 1
Wire diameter and type	.030"	.035"	.045"	.052"	1/16"
Tubular (flux or metal cored)	N/A	N/A	15-36V 105-340A	15-36V 105-430A	15-40V 140-480A
Self-shielded flux cored	N/A	14-20V 50-120A	13-20V 80-220A	N/A	14-22V 146-322A
Solid (MIG)	17-23V 50-200A	18-25V 50-225A	18-34V 85-355A	21-39V 150-500A	26-40V 250-610A

Amperage and Voltage for Wire Electrodes — Part 2
Wire diameter and type	.072"	5/64"	3/32"	7/64"	1/8"
Tubular (flux or metal cored)	22-36V 200-495A	23-33V 250-510A	24-36V 355-615A	N/A	26-32V 375-640A
Self-shielded flux cored	16-25V 130-350A	16-35V 200-545A	16-35V 200-525A	22-33V 310-625A	28-38V 400-600A

Amperage for TIG Welding
Tungsten type & diameter	1/16"	3/32"	1/8"	3/16"	1/4"
2% type	50-140	125-200	150-325	300-340	-
Pure type	60-90	125-160	190-240	260-320	330-450

Amperage for Carbon Arc Gouging
Carbon diameter	3/16"	1/4"	5/16"	3/8"	1/2"
Amperage	250	300	500	600	750