Basic weld symbols

Weld symbols are used to indicate the welding processes used in metal joining operations, whether the weld is localized or “all around”, whether it is a shop or field weld, and the contour of welds. These basic weld symbols are summarized below and illustrated in figure 3-3.

Arc and Gas Weld Symbols. See figure 3-3.

Resistance Weld Symbols. See figure 3-3.

Brazing, Forge, Thermit, Induction, and Flow Weld Symbols.

These welds are indicated by using a process or specification reference in the tail of the welding symbol as shown in figure 3-4.

Brazing, Forge, Thermit, Induction, and Flow Weld Symbols

When the use of a definite process is required (fig. 3-5), the process may be indicated by one or more of the letter designations shown in 3-2.

Weld Symbols : Process reference

Designation of welding process by letters


Letter designations have not been assigned to arc spot, resistance spot, arc seam, resistance seam, and projection welding since the weld symbols used are adequate.

When no specification, process, or other symbol, the tail may be omitted (fig. 3-6). reference is used with a welding

Other Common Welding Symbols. Figures 3-7 and 3-8 illustrate the weld-all-around and field weld symbol, and resistance spot and resistance seam welds.

**Supplementary Weld Symbols. **These symbols are used in many welding processes in congestion with welding symbols and are used as shown in figure 3-3.