The lap joint or the fillet joint is obtained by overlapping the plates and then welding the edges of the plates. The cross-section of the fillet is approximately triangular. The fillet joints may be 1. Single transverse fillet, 2. Double transverse fillet, and 3. Parallel fillet joints.
The fillet joints are shown in Fig. 1. A single transverse fillet joint has the disadvantage that the edge of the plate which is not welded can buckle or warp out of shape.