How to correctly grind Tungsten Electrode for TIG Welding


Electrodes for TIG Welding

correctly grind Tungsten Electrode for TIG Welding

For TIG welding the applied electrode is mainly made of tungsten. Pure tungsten is a very heat-resistant material with a fusion point of approximately 3,380 degrees C.
By alloying tungsten with a few percent of a metal oxide, the conductivity of the electrode can be increased which has the advantage that it can thereby resist a higher current load.
The alloyed tungsten electrodes, therefore, have a longer lifetime and better ignition properties than electrodes of pure tungsten.

The most frequently used metal oxides used for alloying of tungsten are:
• Thorium oxide ThO2
• Zirconium oxide ZrO2
• Lanthanum oxide LaO2
• Cerium oxide CeO2

Tungsten Electrodes dimensions & sizes

Tungsten electrodes are available in different diameters from 0.5 to 8 mm for TIG welding.
The most frequently used dimensions for TIG welding electrodes are 1.6 – 2.4 – 3.2 and 4 mm.
The diameter of the electrode is chosen on basis of the current intensity, which type of electrode is preferred, and whether it is alternating or direct current.

Grind correctly Tungsten for TIG Welding

An important condition for obtaining a good result of TIG welding is that the point of the tungsten electrode must be ground correctly.
When welding is done with direct current and negative polarity, the electrode point should be conical in order to obtain a concentrated arc that will provide a narrow and deep penetration profile. The following thumb rule indicates the relation between the diameter of the tungsten electrode and the length of its ground point.
A small pointed angle gives a narrow weld pool and the larger the pointed angle the wider the weld pool.

Blunting the electrode point to make a flat area with a diameter of about 0.5 mm can increase the lifetime of the tungsten electrode.

For AC TIG welding the tungsten electrode is rounded as during the welding process it is so heavily loaded that it is melted into a half globular form.

Blunting the electrode point to make a flat area with a diameter of about 0.5 mm can increase the lifetime of the tungsten electrode.

For AC TIG welding the tungsten electrode is rounded as during the welding process it is so heavily loaded that it is melted into a half globular form.

Effect of wrong grinded tungsten in welding

In below picture is a more clear illustration of how the wrong grinding or sharpening of the tungsten electrode influences the welding performances:

Tungsten grinders machines

tungsten grinder is a portable piece of equipment that is easy to operate and helps in the repetitiveness of the sharpening. Ideally but not always, dry electrode grinders will feature a “closed process” that limits exposure of tungsten particulates and sharpening powder to the operator. 

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