4. Projection welding

4.1 Principle

This process is also known as projection welding.

It can be used to produce continuous or discontinuous assemblies by superposition; but it differs from spot or seam welding in that the location of current and force on the welding zone is not obtained by the electrodes, but by the geometry of the parts to be welded themselves. It is also a global welding process.

Figure 16 shows three typical examples of boss or boss-like assembly:

• a) welding of two flat sheets. One of the sheets has been stamped with a number of bosses which will be used to locate current and force;

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