The rounded end on a pure tungsten electrode can be prepared by

The rounded end on a pure tungsten electrode can be prepared by

• A. Filing
• B. Using High Frequency
• C. Using Direct Current Electrode Negative
• D. Using Direct Current Electrode Positive

Answer: (D)

Forming a rounded tip on a pure tungsten electrode is achieved by heating the tip with current so the tip melts and the surface tension pulls it into a ball. Using direct current electrode positive concentrates most of the heat at the electrode end, melting the tip and curling it into a rounded shape. This ball end is the preferred tip for many GTAW setups because it helps start and maintain a stable arc. Filing would mechanically alter the tip but doesn’t reliably create the ball and can introduce contamination. High frequency helps with arc starting and stabilization, not with shaping the tip. Direct current electrode negative would push more heat into the workpiece, not the tip, so the end is less likely to ball.

Forming a rounded tip on a pure tungsten electrode is achieved by heating the tip with current so the tip melts and the surface tension pulls it into a ball. Using direct current electrode positive concentrates most of the heat at the electrode end, melting the tip and curling it into a rounded shape. This ball end is the preferred tip for many GTAW setups because it helps start and maintain a stable arc.

Filing would mechanically alter the tip but doesn’t reliably create the ball and can introduce contamination. High frequency helps with arc starting and stabilization, not with shaping the tip. Direct current electrode negative would push more heat into the workpiece, not the tip, so the end is less likely to ball.