For fillet welding, how is convexity determined?

Convexity in fillet welding refers to the profile of the weld bead when viewed from the side, and it is a critical factor in determining the strength and performance of the weld. The height of the weld above the surface is key in assessing convexity because it provides a direct measurement of how pronounced the weld bead is relative to the base materials being joined.

When a weld is too convex, meaning it has a significant height above the substrate compared to its width, it can lead to stress concentrations that might result in weld failure under load. Conversely, a flatter weld may not provide sufficient reinforcement. Therefore, measuring the height gives a clear understanding of how the weld protrudes, allowing for evaluations of weld quality and compliance with specifications.

The other options do not directly relate to the definition of convexity. The width of the weld bead face, while important for general geometry, does not indicate its height. The angle at which the welding rod was held influences the shape but does not define convexity. Similarly, the overall length of the weld is informative regarding the extent of the weld but is not a measure of its profile. Thus, height is the most appropriate criterion for determining convexity in fillet welding.