Visual Testing (VT) Practice Exam

For a given size weld, how does the theoretical throat for a concave fillet weld compare to a convex fillet weld?

1. The same

2. Larger

3. Smaller

4. Equal to the effective throat

The correct answer is: The same

When comparing the theoretical throat of a concave fillet weld to that of a convex fillet weld, it is essential to understand the definitions and characteristics of these weld types. The theoretical throat of a fillet weld is defined as the shortest distance from the weld root to the face of the weld, measured perpendicularly. For both concave and convex fillet welds of the same size, the theoretical throat remains the same because it is determined by the nominal size of the weld rather than its profile shape. While the physical shape of the weld may affect the overall strength and performance of the weld joint, the theoretical throat is a standard measurement that does not change with the curvature of the weld. Therefore, when evaluating the sizes and dimensions of concave and convex fillet welds, regardless of the different visual appearances and stress distributions, the theoretical throat size for a given nominal size remains consistent, leading to the conclusion that they are the same.