What is the term for the bottom edge of a weld or the deepest point of a weld?

The term for the bottom edge of a weld or the deepest point of a weld is known as the weld root. This is the location where the base materials are joined together at the bottom of the weld joint. Understanding this terminology is crucial in welding as the weld root is a significant factor in determining the strength and integrity of the weld.

When properly formed, the weld root ensures adequate penetration of the weld metal into the base materials, contributing to the overall durability of the weld. Additionally, it plays a role in assessing the quality of the weld as well as determining the necessary welding parameters such as speed and heat input. Being able to identify the weld root is essential for weld inspection and for achieving high-quality welding results.

The other terms listed represent different aspects of welding: weld depth refers to how deep the weld penetrates the material, melt through describes an undesirable condition where the weld metal completely penetrates the material leading to a hole, and reinforcement refers to the excess weld material deposited above the surface of the base metal. Each term is relevant in its context but does not define the bottom edge or deepest point of a weld like weld root does.