Why Does a Resistance Spot Weld Often Appear Oval Shaped?

The Causes of Oval Shaped Resistance Spot Welds

A resistance spot weld is a common method used in various industries to join metal sheets together at specific points. However, there are instances where the weld appears oval shaped instead of the desired round shape. This can be attributed to several factors, including misaligned electrode tips and excessive current-on time.

Misaligned Electrode Tips

When the electrode tips are not properly aligned during the welding process, it can result in an oval shaped weld. The misalignment causes the weld to take on an oval figure with a length greater than its width. This can lead to weakened weld joints and poor overall quality of the weld.

Excessive Current-on Time

Excessive current-on time refers to the duration of time that the welding current is applied during the welding process. If the current-on time is too long, it can cause the material to overheat and deform, resulting in an oval shaped weld. This can also lead to issues such as burn-through and spatter, affecting the integrity of the weld.

In conclusion, both misaligned electrode tips and excessive current-on time can contribute to the oval shaping of a resistance spot weld. It is essential for technicians to ensure proper alignment of electrodes and monitor the welding parameters to achieve the desired round weld shape and maintain the quality of the weld joint.