What is the main purpose of a fillet weld?

The main purpose of a fillet weld is to connect two surfaces at right angles. This type of weld is specifically designed to join parts that are positioned perpendicular to each other, such as the corner of a structural member or the edge of a plate with another plate. The geometry of the fillet weld allows it to fill the space between the two surfaces, creating a strong bond that helps to distribute load and resist forces acting on the joint.

Fillet welds are commonly used in various applications, particularly in the construction of frames and structures where components meet at right angles. By providing a robust connection, they are vital for maintaining the integrity and stability of welded assemblies in both aircraft and other engineering structures.