What type of weld bead does a fine, narrow point (15 degrees) of vertex angle create?

A fine, narrow point with a 15-degree vertex angle is designed to focus heat into a smaller area, which promotes deeper penetration during the welding process. This specific bead shape contributes to a narrow weld bead with significant depth, effectively melting and fusing the base materials.

When the vertex angle is small, the heat is more concentrated, allowing for a more efficient transfer of thermal energy into the joint. This increased concentration of heat not only results in a deeper penetration of the weld but also ensures that the surrounding base metal does not become excessively heated, which can be important for preventing warping or distortion.

In contrast, wider vertex angles tend to distribute heat over a larger area, resulting in a wider weld bead but with less penetration into the materials being joined. Therefore, a fine, narrow vertex angle is particularly advantageous when deep penetration is desired, making it clear why this choice leads to a narrow weld bead with deep penetration.