Service manual

TRANSTIG 200 Pi SERVICE MANUAL
4-12
March 31, 2008
4.13 Basic TIG Welding Guide
1. 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.
2. Tungsten Electrode Current Ranges:
Electrode Diameter DC Current (Amps)
0.040” (1.0mm) 30 – 60
1/16” (1.6mm) 60 – 115
3/32” (2.4mm) 100 – 165
1/8” (3.2mm) 135 – 200
5/32” (4.0mm) 190 – 280
3/16” (4.8mm) 250 – 340
Table 4-7: Current Ranges for Various Tungsten Electrode Sizes
3. Tungsten Electrode Types:
Electrode Type
(Ground Finish)
Welding Application Features
Color
Code
Thoriated 2%
DC welding of mild steel,
stainless steel and copper.
Excellent arc starting, Long
life, High current carrying
capacity.
Red
Ceriated 2%
DC welding of mild steel,
stainless steel, copper,
aluminium, magnesium and
their alloys
Longer life, More stable arc,
Easier starting, Wider current
range, Narrower more
concentrated arc.
Grey
Table 4-8: Tungsten Electrode Types
4. Guide for Selecting Filler Wire Diameter:
Filler Wire Diameter DC Current Range (Amps)
1/16” (1.6 mm) 20 - 90
3/32” (2.4 mm) 65 - 115
1/8” (3.2 mm) 100 - 165
3/16” (4.8 mm) 200-350
Table 4-9: Filler Wire Selection Guide
NOTE
The filler wire diameter specified in Table 4-9 is a guide only, other diameter wires may be used
according to the welding application.