hard solder
brazing solder

Hard solder melts at a higher temperature with a torch.

Hard solders are used for brazing, and melt at higher temperatures.

In silversmithing or jewelry making, special hard solders are used that will pass assay.

There are two types of solder; soft solder and hard solder.

Different equipment is usually required since a soldering iron cannot achieve high enough temperatures for hard soldering or brazing.

A temperature of 450 C is usually accepted as the upper limit for soft solders, whereas hard solders have a higher melting point.

Gold solder is used for joining the components of gold jewelry by high-temperature hard soldering or brazing.

Sumerian swords from 3000 BCE were assembled using hard soldering.

In the United States, trisodium phosphate is an approved flux for use in hard soldering joints in medical grade copper plumbing.

"Hard soldering" or "silver soldering" is used to join precious and semi-precious metals such as gold, silver, brass, and copper.

Hard solders, on the other hand, were usually of the same metal as the object they were used on, but alloyed with a few per cent of another metal in order to reduce the melting point.

Hard solders join by interdiffusion at high temperatures with the metals being bonded, so that composition at the join will be somewhere between that of the solder and that of the object.

It has to be remembered that the analysis of a soldered joint will not be identical to the composition of the original solder alloy because, unlike adhesives, hard solders bond with other metals by diffusion.

In this sense it might be an alloy of equal parts copper and zinc, i.e. a brass, used for hard soldering and brazing, or as an alloy, containing lead, that is used instead of bronze.

Brazing (sometimes known as silver soldering or hard soldering) requires a much higher temperature than soft soldering, sometimes over 850 C. As well as removing existing oxides, rapid oxidation of the metal at the elevated temperatures has to be avoided.

(In hard soldering, also referred to as silver soldering and brazing, the solder consists of a different alloy that melts at a much higher temperature and requires the use of a torch that generates much more heat than an ordinary propane torch.

It emerged on the Portuguese market with the objective of producing and supplying solutions for brazing materials, silver and copper brazing solders.