Figure 1-9 Weld preparation for corner joints
Joint Preparations for T-joints
Figure 1-10 Weld preparations for T-joints
Joint Preparations for Edge Joints
Figure 1-11 Weld preparations for edge joints
Joint Preparations for Lap Joints
Figure 1-12 Weld preparations for lap joints
Common Weld Preparations
Figure 1-13 A few typical weld preparations
What are some basic types of welds?
The Groove Weld
As the name implies and the illustration below shows, this is a weld made in a groove between work pieces. See “Common Weld Preparations,” on the opposite page, for some typical weld dimensions.
See Figure 1-14.
Figure 1-14 Parts of a groove weld
Fillet Weld
Fillet welds are triangular in shape and used to join materials that are at right angles to one another in a lap, T-, or corner joint. The face of the weld can be convex or concave. See Figure 1-15 A&B.
Figure 1-15A Parts of a convex fillet weld
Figure 1-15B Parts of a concave fillet weld
Plug and Slot Welds
These welds join two (or more) parts together by welding them at a point other than their edges. They are particularly useful in sheet metal and auto-body work where welds can be completely concealed by grinding and painting. A hole or slot is made in the work-piece facing the welder and weld is made inside the hole. Filler metal completely fills the hole or slot and penetrates into the lower work-piece(s) securing them together. Plug welds are round and slot welds are elongated and rounded at the ends. See Figure 1-16.
Figure 1-16 Examples of plug and slot welds
Intermittent Welds
Note the positions of the welds shown below. See Figure 1-17.
Figure 1-17 Chain intermittent fillet weld (left) and staggered intermittent fillet weld (right)
Welding Terminology
These terms describe the position of the electrode in respect to the weld.
Axis of the weld—an imaginary line drawn parallel to the weld bead through the center of the weld.
Travel angle—is the smallest angle formed between the electrode and the axis of the weld.
Work angle—for a T-joint or corner joint, the smallest angle formed by a plane, defined by the electrode (wire) and the axis of the weld, and the work piece.
Push angle during forehand welding—this is the travel angle during push welding when the electrode (wire) is pointing toward the direction of weld progression.
Drag angle during backhand welding—this is the travel angle during drag welding when the when the electrode (wire) is pointing away from the direction of weld progression.
Travel speed—the velocity or speed of the electrode (wire) along the travel axis, usually in inches/minute or cm/minute.
See Figure 1-18.
Figure 1-18 Orientation of the electrode
TackWeld
Welders place small, initial welds along joints to hold the work pieces in place so the parts remain in alignment when they are welded. Tack welds hold work firmly in position, but can be broken with a cold chisel in the event further adjustment is needed. Beginning welders tend to make them too small. One inch is the standard length of a tack weld. A tack should be as strong as the weld itself as it becomes an integral part of the finished weld.
Figure 1-19 Make sure the work is aligned properly; keep it aligned by welding small sections at intervals to tack the metal in place
Figure 1-21 Joggle weld joint preparation
Joggle Joints
Joggle joints are used where a strong joint and flat surface is needed to join two pieces of sheet metal or light plate. There are hand tools available to put the joggle into sheet metal. They are useful whenever a finished surface concealing the weld is needed and where a butt joint would not work with thin sheet metal. See Figure 1-21.
Stringer and Weave Beads
In a stringer bead the path of the electrode is straight, with no appreciable side to side movement, and parallel to the axis of the weld, while a weave bead has a side-to-side motion which makes the weld bead wider (and the heat-affected zone larger) than that made with a stringer bead.
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