What aspect of a weld does the term "penetration" refer to?

The term "penetration" specifically refers to the depth of weld metal that has fused into the base material during the welding process. Adequate penetration is crucial for ensuring that the weld joint has sufficient strength and integrity. If the penetration is too shallow, it can result in weak welds that may fail under stress. Proper penetration helps achieve a good bond between the weld and the base metal, contributing to the overall performance of the welded assembly. This depth is influenced by several factors, including the type of welding process used, the materials being joined, the technique of the welder, and the settings of the welding equipment.