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A review of techniques to manage penetration variability during TIG welding


TWI Industrial Member Report Summary 556/1996

P C J Anderson and M D F Harvey

This report reviews the welding techniques that may be applied to manage penetration variability due to materials-related problems during TIG welding.


Ideally, the TIG welding process should be capable of continuous, stable operation and repeatable results. However, the increasing use of this process continues to highlight problems, including:

  • Poor tolerances to variations in component dimensions and to mismatches in joint preparation.
  • Weld defects due to variations in the surface cleanliness of the workpiece, quality of the tungsten electrode and shielding gas purity.
  • Variable weld bead penetration characteristics between materials of the same nominal specification.
Whilst the required corrective action for defective welds resulting from inadequate preparation or variations in surface cleanliness, electrode quality or gas purity is readily apparent, for material-related problems determining the solution has often been a matter of trial and error adjustments to the welding procedure.


  • To outline the welding techniques which can be applied to overcome materials- related penetration variability during TIG welding.

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