Why should the grinding marks run lengthwise on the tungsten electrode?

• A. It makes the electrode lighter.
• B. It reduces heat conduction.
• C. Lengthwise grinding reduces the amount of small particles of tungsten contaminating the weld.
• D. It helps hold the electrode.

Answer: (C)

In GTAW, keeping the electrode tip clean is crucial because tiny tungsten particles can contaminate the weld and cause porosity or inclusions. Grinding marks that run lengthwise along the electrode orient surface irregularities with the direction of the arc, which helps minimize the likelihood that small tungsten fragments will break free and enter the molten weld. Longitudinal grinding creates a smoother, more controlled surface, so any debris is less prone to being drawn into the weld pool by the arc and shielding gas. That’s why lengthwise grinding is the preferred prep.