What is Keyhole in Welding?


In the field of welding, keyhole refers to a specific phenomenon that occurs during certain welding processes. Understanding what a keyhole is and how it forms is essential for welders to ensure proper control and quality in their work.

In this article, we will explore the concept of a keyhole in welding, its formation, and its significance in the welding process.

Definition of Keyhole

A keyhole in welding refers to a void or cavity that forms within the molten weld pool during the welding process. It is created by the intense heat generated by the welding arc, which vaporizes the base metal. The vaporized metal creates a cavity that is maintained by the pressure exerted by the surrounding molten metal.

Formation of Keyhole

The formation of a keyhole involves several factors:

Significance of Keyhole in Welding

The presence of a keyhole in the welding process has both advantages and considerations:


The keyhole phenomenon plays a vital role in certain welding processes, allowing for deep penetration and controlled weld pool dynamics. Understanding the formation and significance of a keyhole is essential for welders to achieve high-quality welds.

By mastering the control of keyhole size and shape, welders can optimize welding parameters and produce strong, reliable, and defect-free welds.