Types of Welds. It is important to distinguish between the joint and the weld. Each must be described to completely describe the weld joint. There are many different types of welds, which are best described by their shape when shown in cross section. The most popular weld is the fillet weld, named after its cross-sectional shape. Fillet welds are shown by figure 6-24. The second most popular is the groove weld. There are seven basic types of groove welds, which are shown in figure 6-25. Other** types of welds** include flange welds, plug welds, slot welds, seam welds, surfacing welds, and backing welds. Joints are combined with welds to make weld joints. Examples are shown in figure 6-26. The type of weld used will determine the manner in which the seam, joint, or surface is prepared.
Groove Weld. These are beads deposited in a groove between two members to be joined. See figure 6-27 for the standard types of groove welds.
Surfacing weld (fig. 6-28). These are welds composed of one or more strings or weave beads deposited on an unbroken surface to obtain desired properties or dimensions. This type of weld is used to build up surfaces or replace metal on worn surfaces. It is also used with square butt joints.
Plug Weld (fig. 6-28). Plug welds are circular welds made through one member of a lap or tee joint joining that member to the other. The weld may or may not be made through a hole in the first member; if a hole is used, the walls may or may not be parallel and the hole may be partially or completely filled with weld metal. Such welds are often used in place of rivets.
A fillet welded hole or a spot weld does not conform to this definition.
Slot Weld (fig. 6-28). This is a weld made in an elongated hole in one member of a lap or tee joint joining that member to the surface of the other member that is exposed through the hole. This hole may be open at one end and may be partially or completely filled with weld metal.
A fillet welded slot does not conform to this definition.
Fillet Weld (top, fig. 6-28). This is a weld of approximately triangular cross section joining two surfaces at approximately right angles to each other, as in a lap or tee joint.
Seam Weld (fig. 6-29). A weld made by arc seam or resistance seam welding. Where the welding process is not specified, this term infers resistance seam welding.
Spot Weld (fig. 6-29). A weld made by arc spot or resistance spot welding. Where the welding process is not specified, this term infers a resistance spot weld.
Upset Weld (fig. 6-29). A weld made by upset welding.