Spot Welding __________.

Spot welding is a specific welding process that involves using electrical resistance and pressure to join metal surfaces together. This technique creates localized welds at specific points, which makes it highly efficient for joining thin sheets of metal, commonly encountered in the automotive and manufacturing industries.

In spot welding, an electric current is passed through the metal pieces being joined, generating heat due to electrical resistance. This heat melts the metal at the weld points, and simultaneous pressure is applied to fuse the materials together as they cool, forming a strong bond. This ability to create quick, localized welds makes spot welding ideal for assembly processes where speed and efficiency are critical.

The other options are not accurate descriptions of spot welding. For instance, it is not synonymous with tack welding; tack welding refers to temporary welds used to hold pieces in place before the final welding takes place. Unlike the assertion in one of the options, spot welding does indeed require electricity to facilitate the process. Lastly, spot welding remains a prevalent technique in manufacturing, particularly in mass production scenarios, and is not rare as suggested by another option.