What is the difference between a hot weld and a cold weld?

The distinction between a hot weld and a cold weld primarily lies in the level of heat used during the welding process and the resulting quality of the weld. A hot weld, created with sufficient heat, achieves good penetration, ensuring that the metal pieces fuse together adequately. This process involves melting the base metals and allowing them to bond effectively, creating a strong and durable joint.

In contrast, a cold weld occurs when the materials are not heated sufficiently, leading to inadequate fusion between the two surfaces. As a result, a cold weld is prone to lack of strength and integrity, meaning the joint may fail under stress. This option emphasizes the quality-related aspects of the welds, illustrating that penetration is critical for achieving a robust connection, which is a fundamental principle in welding.

The other options, while touching on aspects of the welding process, do not clearly capture the primary difference of penetration and fusion quality that defines hot and cold welds.