Editing Solder (section)

=== Hard solder ===
[[File:Silver solder.jpg|thumb|Silver solders (Ag/Cu/Zn) marked with their different hardness. From no.1="repair" to no.5="enameling".]]
[[File:Gold solder.jpg|thumb|Gold solders (Au/Ag/Cu/Zn) marked with their different hardness. From no.1=lowest temp to no.3=highest temp.]]
Hard solders are used for brazing, and melt at higher temperatures. Alloys of copper with either zinc or silver are the most common.

In [[silversmithing]] or [[jewelry]] making, special hard solders are used that will pass [[Metallurgical assay|assay]]. They contain a high proportion of the metal being soldered and lead is not used in these alloys. These solders vary in hardness, designated as "enameling", "hard", "medium", "easy" and "repair". [[Vitreous enamel|Enameling]] solder has a high melting point, close to that of the material itself, to prevent the joint [[desoldering]] during firing in the enameling process. The remaining solder types are used in decreasing order of hardness during the process of making an item, to prevent a previously soldered seam or joint desoldering while additional sites are soldered. Easy solder or repair solder are also often used for repair work for the same reason. Flux is also used to prevent joints from desoldering.

Silver solder is also used in manufacturing to join metal parts that cannot be [[welding|welded]]. The alloys used for these purposes contain a high proportion of silver (up to 40%), and may also contain [[cadmium]].