1. Be careful with broken or pinched electrode tip

If you look at a tungsten electrode tip, greatly enlarged, you can clearly see the so-called grain size in the material, which is characterized by light and dark areas. Every boundary from one area to the other represents the grain boundary. Tungsten electrodes have their weak point when subjected to mechanical stress along the grain boundary. This means: A pinched or worn TIG welding electrode is weakened at the grain boundaries. If this is now sharpened, something similar happens that, figuratively, is known from pencil sharpening with a blunt sharpener: The material does not tear open nicely.

The heat during welding can cause cracks to form at the tip if the grain boundary is damaged. When grinding the tungsten electrode, you have to proceed very carefully so that the grain boundary is not damaged. The pressure for sharpening should also only be light. If the pressure is too great, heat builds up, which in turn can damage the grain boundary.

2. Never sharpen the TIG welding electrode freehand

Angle grinder, whetstone or abrasive mop – there are the most adventurous approaches to sharpen tungsten electrodes manually. In any case, do not try to grind the tungsten electrode freehand! For a good welding result, the tip must be concentric and the sharpening surface smooth. Even with very steady hand control, you would never get a perfect tungsten electrode cut. And this is especially important when the weld seam is more demanding. In addition, grinding by hand is never exactly the same a second time. However, repeatable parameters are the be-all and end-all for consistently good resp. high quality.

3. The right sharpening direction for tungsten electrodes: axial instead of radial

When sharpening the TIG welding electrode, the grinding direction is decisive: If the grinding is transverse, i. e. radial to the welding electrode, a wide arc cone is generated. The penetration depth is then smaller, which as a result leads to root binding errors, for example in the case of an i-joint. If, on the other hand, the cut is longitudinal to the electrode, i. e. axially, the arc is more focused, enables deeper penetration and thus makes it easier for the weldder to apply the energy with pinpoint accuracy.

There is a rule of thumb: the tip of the tungsten electrode should be twice as long as its diameter.

4. Sharpening at the correct angle

You get the best welding result with the correct grinding angle. The sharper the TIG welding electrode is ground, the more targeted and narrow the penetration. At the same time, however, the load on the electrode tip is extremely high, which in turn limits its service life. With an extreme peak of, for example, 30 °, tungsten can get into the weld pool and then contaminate it. If, on the other hand, the tungsten electrode is blunt-pointed and you weld with it at the same welding current as with the sharpened electrode, the penetration is wider and less focused. We recommend a grinding angle of 60 ° for TIG welding electrodes in order to achieve the best welding results.

5. Flatten the electrode tip after sharpening

We recommend you flatten or blunt the tip of the tungsten electrode after sharpening. The guideline for this is approx. ten percent of the electrode diameter – an electrode with a diameter of 1.6 mm then has a blunt tip of approx. 0.15 mm. The flattened tip has a positive effect on the electrode exit because it prevents particles from breaking out of the tungsten electrode tip. In addition, the flat surface grinding of the tip puts less stress on the electrode and thus extends the service life of this wear part.