solder: An alloy used to join metalsurfaces. A soft solder melts at a temperaturein the range 200–300°C andconsists of a tin–lead alloy. The tincontent varies between 80% for thelower end of the melting range and31% for the higher end. Hard solderscontain substantial quantities of silverin the alloy. Brazing solders areusually alloys of copper and zinc,which melt at over 800°C.
An alloy used in joining
metals. The molten solder wets the surfaces to be joined, without melting them, and solidifies on cooling to form a hard joint. The
surfaces must be clean and free of oxide
and a flux is often used to achieve this. Soft
solders consist of lead with up to 60% tin
and melt in the range 183–250°C. Soft-soldering is used, for example, in plumbing
and making electrical contacts. Brazing
solders are copper–zinc alloys that have
higher melting points and produce stronger
joints than soft solders; silver can be added
to produce silver solders.
A low-melting alloy usually of the lead-tin
type used for joining metals at temperatures below
425C. The solder acts as an adhesive and does not
form an intermetallic solution with the metals being
joined.
