Basic Tig Welding Guide; Electrode Polarity; Tungsten Electrode Current Ranges; Tungsten Electrode Types - Thermal Arc pro-life 250s Operating Manual

7.0 BASIC TIG WELDING GUIDE

7.01Electrode 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.

7.02 Tungsten Electrode Current Ranges

Table 4 – Current ranges for varies tungsten electrode sizes

7.03 Tungsten Electrode Types

Electrode Type
(Ground
Finish)
Thoriated 2%
Ceriated 2%
37
Electrode Diameter
0.040" (1.0mm)
1/16" (1.6mm)
3/32" (2.4mm)
1/8" (3.2mm)
5/32" (4.0mm)
3/16" (4.8mm)
Welding Application
DC welding of mild steel,
stainless steel and copper.
DC welding of mild steel,
stainless steel, copper,
aluminium, magnesium and
their alloys
Table 5 – Tungsten electrode types
DC Current (Amps)
30 – 60
60 – 115
100 – 165
135 – 200
190 – 280
250 – 340
Features
Excellent arc starting, Long
life, High current carrying
capacity.
Longer life, More stable arc,
Easier starting, Wider current
range, Narrower more
concentrated arc.
PRO-LITE 250S
Color
Code
Red
Grey
June 29, 2005