Tweco 250i Transmig Inverter - Manual (Page 74)

TRANSMIG 250I BASIC WELDING
BASIC WELDING 4-18 Manual 0-5187
4.05 TIG (GTAW) Basic Welding Technique
Gas Tungsten Arc Welding (GTAW) or TIG (Tungsten Inert Gas) as it is commonly referred to, is a welding process in
which fusion is produced by an electric arc that is established between a single tungsten (non-consumable) electrode
and the work piece. Shielding is obtained from a welding grade shielding gas or welding grade shielding gas mixture
which is generally Argon based. A filler metal may also be added manually in some circumstances depending on the
welding application.
Welds Made With or Without
Addition of Filler Metal
Work Piece
Can Be Any Commercial
Metal
Gas Cup
Either Ceramic,
High-lmpact or
Water Cooled
Metal
Inert Gas
Shields Electrode
and Weld Puddle
Tungsten Electrode
Non-Consumable
A-09658_AB
Figure 4-40: TIG Welding Application Shot
Tungsten Electrode Current Ranges
Electrode Diameter DC Current (Amps)
1.0mm 30-60
1.6mm 60-115
2.4mm 100-165
3.2mm 135-200
4.0mm 190-280
4.8mm 250-340
Table 4-6: Current Ranges for Various Tungsten Electrode Sizes
Guide for Selecting Filler Wire Diameter
Filler Wire Diameter DC Current Range (Amps)
1.6mm 20-90
2.4mm 65-115
3.2mm 100-165
4.8mm 200-350
Table 4-7: Filler Wire Selection Guide