2.5 Welding wire selection
The following table includes the recommended welding consumable for the most commonly
welded materials.
Base material
BOC Consumable
C-Mn and low carbon steels
BOC Mild steel TIG wire
Low Alloy steels
1.25Cr/0.5Mo
Comweld CrMo1
2.5Cr/1Mo
Comweld CrMo2
Stainless Steel
304/304L
Profill 308
316/316L
Profill 316
309/309-C-Mn
Profill 309
321/Stabilised grades
Profill 347
Filler rod diameter (mm)
Thickness of metal (mm)
2
0.5 – 2
3
2 – 5
4
5 – 8
4 or 5
8 – 12
5 or 6
12 or more
2.6 Tungsten electrode selection
Base
metal
type
Thickness
range
Desired
results
Welding
current
Electrode
type
Shielding
gas
Tungsten performance
characteristics
Copper al
lo
ys
, C
u-NI al
lo
ys and
Nick
el
al
lo
ys
All
General
purpose
DCSP
2%
Thoriated
(EW-Th2)
75% Argon/
25% Helium
Best stability at medium
currents. Good arc starts
Medium tendency to spit
Medium erosion rate
2% Ceriated
(EW-Ce2)
75% Argon/
25% Helium
Low erosion rate. Wide current
range. AC or DC. No spitting.
Consistent arc starts
Good stability
Only thick
sections
Increase
penetration
or travel
speed
DCSP
2% Ceriated
(EW-Ce2)
75% Argon/
25% Helium
Low erosion rate. Wide current
range. AC or DC. No spitting.
Consistent arc starts
Good stability
Mild S
teels
, Carbon S
teels
, Al
lo
y S
teels
,
Stainle
ss
S
teels and Titanium al
lo
ys
All
General
purpose
DCSP
2%
Thoriated
(EW-Th2)
75% Argon/
25% Helium
Best stability at medium
currents. Good arc starts
Medium tendency to spit
Medium erosion rate
2% Ceriated
(EW-Ce2)
75% Argon/
25% Helium
Low erosion rate. Wide current
range. AC or DC. No spitting
Consistent arc starts
Good stability
2%
Lanthanated
(EWG-La2)
75% Argon/
25% Helium
Lowest erosion rate. Widest
current range on DC. No spitting.
Best DC arc starts and stability
Only thick
sections
Increase
penetration
or travel
speed
DCSP
2% Ceriated
(EW-Ce2)
75% Argon/
25% Helium
Low erosion rate. Wide current
range. No spitting. Consistent arc
starts. Good stability
2%
Lanthanated
(EWG-La2)
Helium
Lowest erosion rate. Highest
current range. No spitting. Best
DC arc starts and stability
BOC Smootharc TIG 185 Operating Manual
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BOC Smootharc TIG 185 Operating Manual