MAINTENANCE AND TROUBLESHOOTING
Tungsten Electrodes Rating for Welding Currents
Tungsten
Diameter
mm
DC Current Amps
Torch Negative
2% Thoriated
AC Current Amps
Un-Balanced Wave
0.8% Zirconiated
AC Current Amps
Balanced Wave
0.8% Zirconiated
1.0mm
15-80
15-80
20-60
1.6mm
70-150
70-150
60-120
2.4mm
150-250
140-235
100-180
3.2mm
250-400
225-325
160-250
4.0mm
400-500
300-400
200-320
3.3.6 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.
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