« Back to Dictionary Index

Arc Blow

Arc blow is a welding term that refers to the tendency for an arc to wander or deviate from its intended path during arc welding. This phenomenon is primarily caused by magnetic forces.


  • Causes:
  • Magnetic fields generated by the welding current can create forces that influence the arc’s stability.
  • These magnetic fields can arise from various sources, including the workpiece, welding cables, or other nearby magnetic materials.
  • Effects:
  • Arc blow can lead to inconsistent weld quality, affecting the appearance and strength of the weld.
  • It can cause the arc to blow to one side, resulting in undercutting, porosity, and other weld defects.
  • Mitigation:
  • Adjusting the welding current and electrode angle can help minimize arc blow.
  • Repositioning ground clamps or using alternating current (AC) instead of direct current (DC) can also reduce the effects of arc blow.
  • Implementing magnetic arc blow control devices or using techniques such as backstepping can further mitigate this issue.

Understanding and controlling arc blow is crucial for achieving high-quality welds and maintaining the structural integrity of welded components.

« Back to Dictionary Index