Tungsten tip preparation
= Diameter
Taper length
2–3x Dia
Flat
1/4–1/2x Dia
DCSP (EN) or DCRP (EP)
Max. ball
1x Dia
ACHP General Purpose
Ball tip by arcing on clean metal at low current DCRP (EP) then slowly
increase current to form the desired ball diameter. Return setting to AC.
Tungsten grinding
Shape by grinding longitudinally (never
radially). Remove the sharp point to
leave a truncated point with a flat
spot. Diameter of flat spot determines
amperage capacity (See below).
The included angle determines weld
bead shape and size. Generally, as the
included angle increases, penetration
increases and bead width decreases.
Use a medium (60 grit or finer)
aluminium oxide wheel.
Tungsten extension
General
purpose
3x Dia
Standard Parts
General
purpose
3x Dia
Maximum
6x Dia
Gas Lens Parts
(in draft free areas)
Tungsten electrode tip shapes and current ranges
Thoriated, ceriated, and lanthanated tungsten electrodes do not ball
as readily as pure or zirconiated tungsten electrodes, and as such are
typically used for DCSP welding. These electrodes maintain a ground
tip shape much better than the pure tungsten electrodes. If used on
AC, thoriated and lanthanated electrodes often spit. Regardless of the
electrode tip geometry selected, it is important that a consistent tip
configuration be used once a welding procedure is established. Changes
in electrode geometry can have a significant influence not only on the
weld bead width, depth of penetration, and resultant quality, but also on
the electrical characteristics of the arc. Below is a guide for electrode tip
preparation for a range of sizes with recommended current ranges.
Tungsten electrode tip shapes and current ranges
Electrode
diameter (mm)
Diameter arc
tip (mm)
Constant
included angle,
(degrees)
Current range
(A)
1.0
0.125
12
2 – 15
1.0
0.250
20
5 – 30
1.6
0.500
25
8 – 50
1.6
0.800
30
10 – 70
2.3
0.800
35
12 – 90
2.3
1.100
45
15 – 150
3.2
1.100
60
20 – 200
3.2
1.500
90
25 – 250
13
BOC Smootharc TIG 185 AC/DC Operating Manual
Summary of Contents for Smootharc TIG185 AC/DC
Page 1: ...Smootharc TIG185 AC DC Operating Manual...
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