Inconsistent Weld Quality


Weld quality varies with some welds failing to meet applicable quality standards.


Quality may vary as a result of a trend (Fig. 1) or in a more random pattern (Fig. 2).

Inconsistent Weld Quality Figure - Production Engineering

Fig. 1

Inconsistent Weld Quality Figure 2 - Production Engineering

Fig. 2

  • A gradual decrease in weld quality (Fig. 1) can occur because of an increase in the face diameter of the tips. Random variation about this trend may eventually fall below the minimum standards. Countermeasures to address the trend may include current steppers, tip-dressing etc.
  • More random variation (Fig. 2) may occur due to intermittent factors such as voltage sag and spike, workpiece surface variation, etc. Further system analysis may be required to determine the root cause of the variation.


Inconsistent weld quality can be determined through properly scheduled quality checks.


Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition.

Possible Causes

Strong Possibilities

Weak Possibilities

Nonmatrix Possibilities

  • Interference due to other operations, electro-magnetic interference from nearby sources
  • Power system surges or drops