5.4.1 Types of Welds

Welded joints are classified according to the relative position of the mating components [Fig. 5.17]:

1. Butt Joint
   A butt joint is formed by lying the two components in the same plane and mating the edges to be welded. For plates thicker than 6 mm, the edges of the plates are to be beveled on single side, while for thickness more than 20 mm, both sides of edges are beveled to form double beveled butt joints.
2. Lap Joint
   Two overlapping components form a lap joint. A fillet weld consists of an approximately triangular cross-section joining two surfaces at right angle to each other.
3. Tee Joint
   When end face of one component is welded to a side of the other component, the joint formed is called tee joint. The weld can be made on single side or both sides.
4. Corner Joint
   A corner joint consists of an approximately triangular cross-section, joining two surfaces at right angle to each other.
5. Edge Joint
   An edge joint is formed by mating the parallel edges of the mating components. Edge joints are not recommended for plates thicker than 6 mm.

Figure 5.17 Types of welds
(a) Butt joint  (b) Lap joint  (c) Tee joint  (d) Corner joint  (e) Edge joint

Various techniques of welding are discussed separately in Chapter 13.