Scope - This report is an abbreviated summary of metallurgical joining by welding, brazing, and soldering. It is generally intended to reflect current usage in the automotive industry; however, it does include some of the more recently developed processes. More comprehensive coverage of materials, processing details, and equipment required may be found in the Welding Handbook, Soldering Manual, and other publications of the American Welding Society and the American Society for Testing and Materials. AWS Automotive Welding Committee publications on Recommended Practices are particularly recommended for the design or product engineer.

This report is not intended to cover mechanical joining such as rivets or screw fasteners, or chemical joining processes such as adhesive joining.

Classification of Welding Processes - Current welding practices utilize a great variety of other welding processes not covered in the scope of this report. The AWS has classified all these processes in their Master Chart of Welding Processes (Figure 1).

Standard Welding Symbols

With the advancement of welding technology, more welding variables and controls are being continuously added to the manufacturing requirements of weldments. These may include:

Dimensional requirements of welds (size, length, pitch, number of welds, etc.).

Integrity requirements, such as shear strength for resistance welds, depth of penetration, etc.

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Performance requirements of welds and welded joints. These may include:

Dimensional requirements (joint preparation, root opening, etc.).

Process requirements (series, direct, indirect, over and under welding, and process designations).

Other requirements such as weld all around, field weld, etc.

Symbols provide a universal means of communicating the above referenced information from the product designer to the process man without the risk of misinterpretation. Internationally accepted process and weldment symbols are shown in Figure 2.

Automotive Welding Applications - Certain welding processes have made further inroads in the area of automotive welding than others. This fact is caused not only by their greater adaptability to perform automotive welds, but also by keeping up with high production requirements at lower costs. At the present time the following processes are being used extensively:

a. Resistance welding processes.

b. Arc welding processes.

c. Brazing and soldering.

d. Special process.