－
14
－
8.1.2 Selection of Electrode Diameter
Apply welding current within the range specified in Table 8.2 according to electrode diameter.
Table 8.2 Relationship between Electrode Diameter and Welding Current
Welding current
(
A
)
DC TIG Welding
(
negative electrode
)
AC TIG Welding
Electrode
diameter
mm
φ
Ceriated tungsten
Thoriated tungsten
Ceriated tungsten Pure tungsten
Thoriated tungsten
0.5
-
1
～
20
-
30
50
1.0
-
1
～
80
-
10
～
60
20
～
80
1.6
5
～
150
5
～
150
40
～
130
20
～
100
40
～
130
2.0
-
10
～
200
-
30
～
130
50
～
180
2.4
20
～
250
20
～
250
70
～
220
50
～
160
70
～
220
3.0
-
40
～
350
-
80
～
190
90
～
260
3.2
50
～
400
50
～
400
110
～
290
100
～
210
110
～
290
4.0
-
80
～
500
-
150
～
270
170
～
360
Note: This table describes the standard ranges of welding current that differ according to electrode diameter.
8.2 Selection of Collet and Collet Body
A collet and a collet body are for feeding and holding electrode. They are divided into two kinds depending on
whether they have gas lenses. (Ones for gas lenses are incorporated as standards.)
Use a right collet and a collect body according to the size.
8.3 Selection of Nozzle
In order to have a sufficient shielding effect of argon gas, see Table 8.3 and use a right nozzle according to
welding current.
Nozzles have good electric insulation, and they especially have excellent shock-resistance and heat-resistance.
The relationship between welding current and nozzle diameter is described in Table 8.4, and the relationship
between nozzle No. and inside diameter in Table 8.4.
Table 8.3 Relationship between Welding Current and Nozzle Diameter
DC TIG Welding
(
negative electrode
)
AC TIG Welding
Welding current
(
A
)
Nozzle No.
Gas flow rate
Nozzle No.
Gas flow rate
10
～
100
4,5,6
4
～
5
ｌ/cm
2
5,6
6
～
8
ｌ/cm
2
101
～
150
4,5,6
5
～
7
ｌ/cm
2
6,7
7
～
10
ｌ/cm
2
151
～
200
4,5,6,7,8
6
～
8
ｌ/cm
2
7,8
7
～
10
ｌ/cm
2
201
～
300
5,6,7,8
8
～
9
ｌ/cm
2
8,10,12
8
～
15
ｌ/cm
2
Table 8.4 Relationship between Nozzle No. and Inside Diameter
Nozzle No.
4
5
6
7
8
10
12
Inside
diameter(mm)
6.5
8
9.5
11
12.7
16
19
