Electrode Polarity; Tungsten Electrode Current Ranges; Tungsten Electrode Types - Thermal Arc ARCMASTER 300 AC/DC Operating Manual

ARCMASTER 300 ACDC

7.02 Electrode Polarity

Connect the TIG torch to the - / TORCH terminal and the work lead to the + / WORK terminal for direct current straight
polarity. Direct current straight polarity is the most widely used polarity for DC TIG welding. It allows limited wear of
the electrode since 70% of the heat is concentrated at the work piece.

7.03 Tungsten Electrode Current Ranges

Electrode Diameter
0.040" (1.0mm)
1/16" (1.6mm)
3/32" (2.4mm)
5/32" (4.0mm)
3/16" (4.8mm)

7.04 Tungsten Electrode Types

Electrode Type
(Ground Finish)
Thoriated 2%
Zirconated 1%
Ceriated 2%
7-2
AC Current (Amps)
1/8" (3.2mm)
Table 7-2: Current ranges for various tungsten electrode sizes
Welding Application
DC welding of mild steel,
stainless steel and copper.
High quality AC welding of
aluminium, magnesium and
their alloys.
AC & DC welding of mild steel,
stainless steel, copper,
aluminium, magnesium and
their alloys
Table 7-3: Tungsten electrode types
DC Current (Amps)
30 – 70
60 – 95
125 – 150 100 – 165
130 – 225 135 – 200
190 – 280 190 – 280
250 – 340 250 – 340
Features
Excellent arc starting, Long life,
High current carrying capacity.
Self cleaning, Long life,
Maintains balled end, High
current carrying capacity.
Longer life, More stable arc,
Easier starting, Wider current
range, Narrower more
concentrated arc.
30 – 60
60 – 115
Color
Code
Red
White
Grey
Februrary 22, 2006