Which of the following is not a valid contour for the finished shape of a weld?

The finished shape of a weld can take various contours, each designed to meet specific strength and aesthetic requirements. Among the given options, the choice that is not considered a valid weld contour is the square shape.

Weld contours are typically classified based on their geometric profiles that contribute to how the weld integrates with the base materials. Common valid shapes include round, fillet, and bevel.

• Round contours are often utilized to provide a smooth and rounded finish, which helps in distributing stress evenly and minimizing stress concentrations.

• Fillet welds create a triangular cross-section that effectively joins two surfaces at right angles, commonly used for corner joints and T-joints, making them quite versatile in structural applications.

• Bevel welds involve beveling the edges of the materials being joined, allowing for deeper penetration and a stronger joint in thicker materials.

The square shape, however, does not indicate a recognized contour for a completed weld, as welds typically aim for shapes that help with strength, fluidity, and appearance, rather than the straightforward square profile which does not aid in these aspects as effectively.