Arcmaster, 300 s – Tweco 300 S Arcmaster User Manual

Page 33

ARCMASTER

300 S

March 31, 2006

7-1

SECTION 7:

BASIC TIG WELDING GUIDE

7.01 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.

7.02 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 – Current ranges for varies tungsten electrode sizes

7.03 Tungsten Electrode Types

Electrode Type

(Ground Finish)

Welding Application

Features

Color

Code

Thoriated 2%

Ceriated 2%

Red

Grey

DC welding of mild steel,
stainless steel and copper.

Excellent arc starting, Long life,
High current carrying capacity.

DC welding of mild steel,
stainless steel, copper,

i i

Longer life, More stable arc,
Easier starting, Wider current

Table 5 – Tungsten electrode types

7.04 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 6 – Filler wire selection guide

NOTE

The ﬁ ller wire diameter speciﬁ ed in Table 6 is a
guide only, other diameter wires may be used
according to the welding application.