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Tungsten Electrodes
Tungsten is a rare metallic element used for manufacturing TIG welding electrodes. The TIG process
relies on
tungsten‘s
hardness and high-temperature resistance to carry the welding current to the arc.
Tungsten has the highest melting point of any metal, 3,410 degrees Celsius.
Tungsten electrodes are non consumable and come in a variety of sizes, they are made from pure
tungsten or an alloy of tungsten and other rare earth elements. Choosing the correct tungsten depends
on the material being welded, the amount of amps required and whether you are using AC or DC
welding current.
Follow are common used tungsten types: Thoriated, Ceriated, Lanthanated, Zirconiated
Tungsten Electrodes Rating for Welding Currents
Tungsten
Diameter
mm
DC Current
Amps
Torch Negative
2% Thoriated
1.0mm
15 - 80
1.6mm
70 -150
2.4mm
150 - 250
3.2mm
250 - 400
4.0mm
400 - 500
Tungsten Preparation
Always use DIAMOND wheels when grinding and cutting. While tungsten is a very hard material, the
surface of a diamond wheel is harder, and this makes for smooth grinding. Grinding without diamond
wheels, such as aluminium oxide wheels, can lead to jagged edges, imperfections, or poor surface
finishes not visible to the eye that will contribute to weld inconsistency and weld defects.
Always ensure to grind the tungsten in a longitudinal direction on the grinding wheel. Tungsten
electrodes are manufactured with the molecular structure of the grain running lengthwise and thus
grinding crosswise is ―grinding against the grain.‖ If electrodes are ground crosswise, the electrons
have to jump across the grinding marks and the arc can start before the tip and wander . Grinding
longitudinally with the grain, the electrons flow steadily and easily to the end of the tungsten tip. The
arc starts straight and remains narrow, concentrated, and stable.
Tungsten Diameter Rating for Angle and Current
Tungsten
Diameter
Constant
Included
Angle -
Degrees
Current
Range Amps
1.0mm
20
05 - 30
1.6mm
25
08 - 50
1.6mm
30
10 - 70
2.4mm
35
12 - 90
2.4mm
45
15 - 150
3.2mm
60
20 - 200
3.2mm
90
25 - 250
Summary of Contents for SI-TIG-300
Page 31: ... 28 9 TIG WELDING TORCH DETAILS ...
Page 32: ... 29 ...
Page 33: ... 30 10 ARGON FLOWMETER REGULATOR DETAILS ...
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