General Science

  • noun an alloy with a low melting point, typically a mixture of tin and lead, used to join metallic parts
  • verb to join parts using solder

Cars & Driving

  • noun an alloy which is melted to form a joint between two metal surfaces; typically, soft solders are alloys of lead and tin, whilst hard solders are alloys of copper and zinc
  • verb to join together using solder


  • An alloy, usually lead-tin, with a melting point below 800°F (427°C), used to join metals or seal joints.
  • The process of joining metals or sealing joints using solder and heat.


  • A metal or alloy that is utilized to join two metals, such as the leads of circuit components to conductive potions of printed circuits. The solder must have a lower melting point than that which is to be joined, as the former is melted, and the latter is not. Solders with comparatively low melting points, such as an eutectic alloy of tin and lead, are called soft solders, while those with comparatively high melting points, such as an alloy of silver, copper, and zinc, are called hard solders. A solder flux may be utilized to help prepare a surface for soldering.
  • To join surfaces with solder (1).

Origin & History of “solder”

To solder something is etymologically to make it ‘solid’. The word was originally acquired, as a noun, from Old French soldure, a derivative of the verb solder ‘solder’. this in turn came from Latin solidāre ‘make solid, strengthen, fasten’, a derivative of solidus ‘solid’ (source of English solid).