Types of Welded Joints

Following two types of welded joints are important from the subject point of view:

·         Lap joint or fillet joint, and

·         Butt joint.

Lap Joint

 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

·         Single transverse fillet,

·         Double transverse fillet, and

·         Parallel fillet joints.

 The fillet joints are shown in Fig. 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.

Butt Joint

 The butt joint is obtained by placing the plates edge to edge as shown in Fig. 10.3. In butt welds, the plate edges do not require bevelling if the thickness of plate is less than 5 mm. On the other hand, if the plate thickness is 5 mm to 12.5 mm, the edges should be bevelled to V or U-groove on both sides.

The butt joints may be

Square butt joint,

Single V-butt joint

Single U-butt joint,

Double V-butt joint, and

Double U-butt joint.