Spot welder is a term that is used to refer to a special type of welding machine that is designed for spot welding of various metal materials. However, if you are searching for alternatives to the term, some of the synonyms that can be used include "spot welding equipment", "point welding machine", "resistance welding machine" or "spot welding gun". These terms all describe similar machines and equipment that are used in a wide range of industries for welding purposes. They are often used interchangeably, and the choice of synonym will depend on the user's preference and familiarity with the term used in their particular industry.