Thermal Arc ARCMASTER 185 AC/DC, Operating Manual, Page: 40 / 74

ARCMASTER 185 AC/DC
7-2 Feb r ua r y 20, 2006
7.02 Electrode Polarity
Connect the TIG to r ch to the - / TORCH te r minal and the wo r k lead to the + / WORK te r minal fo r di r ect cu rr ent st r aight
pola r ity. Di r ect cu rr ent st r aight pola r ity is the most widely used pola r ity fo r DC TIG welding. It allows limited wea r of
the elect r ode since 70% of the heat is concent r ated at the wo r k piece.
7.03 Tungsten Electrode Current Ranges
Electrode Diameter AC Current (Amps) DC Current (Amps)
0.040” (1.0mm) 30 – 70 30 – 60
1/16” (1.6mm) 60 – 95 60 – 115
3/32” (2.4mm) 125 – 150 100 – 165
1/8” (3.2mm) 130 – 225 135 – 200
5/32” (4.0mm) 190 – 280 190 – 280
3/16” (4.8mm) 250 – 340 250 – 340
Table 7-2: Cu rr ent r anges fo r va r ious tungsten elect r ode sizes
7.04 Tungsten Electrode Types
Electrode Type
(Ground Finish)
Welding Application Features Color
Code
Tho r iated 2%
DC welding of mild steel,
stainless steel and coppe
r
Excellent a r c sta r ting, long life,
high cu rr ent ca rr ying capacity Red
Zi r conated 1%
High quality AC welding of
aluminium, magnesium and
thei
r alloys
Self cleaning, long life,
maintains balled end, high
cu
rr ent ca rr ying capacity
White
Ce r iated 2%
AC & DC welding of mild
steel, stainless steel, coppe
r ,
aluminium, magnesium and
thei
r alloys
Longe r life, mo r e stable a r c,
easie r sta r ting, wide r cu rr ent
r ange, na rr owe r mo r e
concent r ated a r c
G r ey
Table 7-3: Tungsten Elect r ode Types