What is considered acceptable to ensure a weld is structurally sound?

The notion of structural soundness in welding is critically tied to the integrity and quality of the welds themselves. The best indicator of this integrity is that the welds should be free from visual defects. Visual inspection is often the first line of evaluation for weld quality, allowing for the identification of common issues such as cracks, undercuts, porosity, or poor fusion that may compromise the weld's strength and performance.

While other factors, like adherence to minimum standards, can be important, they do not adequately guarantee that a weld will perform reliably under load. A weld may technically meet minimum specification requirements but still aesthetically exhibit defects that could lead to failure. Therefore, ensuring that welds are visually defect-free significantly boosts confidence in their structural soundness, making this choice the most reliable option.

The other choices fall short in various ways. Relying only on fillet welds ignores the circumstances under which different types of welds, such as groove welds, might be more appropriate. The mention of hashed marks does not correspond to any standard or acknowledged method for assessing weld quality. Lastly, while a weld meeting minimum standards indicates a baseline level of acceptance, it does not account for the potential presence of defects, which are critical in assessing structural integrity.