What is "solder"

Solder \Sol"der\, n. [Formerly soder; F. soudure, OF. soudeure, fr. OF. & F. souder to solder, L. solidare to fasten, to make solid. See Solid, and cf. Sawder.] A metal or metallic alloy used when melted for uniting adjacent metallic edges or surfaces; a metallic cement. Hence, anything which unites or cements.

Hard solder, a solder which fuses only at a red heat, as one composed of zinc and copper, or silver and copper, etc.

Soft solder, a solder fusible at comparatively low temperatures; as, plumbers' solder, consisting of two parts lead and one part tin, is a soft solder.

Solder \Sol"der\, v. t. [imp. & p. p. Soldered; p. pr. & vb. n. Soldering.] [Formerlysoder. See Solder, n.]

1. To unite (metallic surfaces or edges) by the intervention of a more fusible metal or metallic alloy applied when melted; to join by means of metallic cement.

2. To mend; to patch up. ``To solder up a broken cause.''
   --Hooker.

mid-14c., sawd "mend by soldering," from solder (n.). Modern form is a re-Latinization from early 15c. Related: Soldered; soldering.

early 14c., soudur, from Old French soldure, soudeure, from souder, originally solder, "to consolidate, close, fasten together, join with solder" (13c.), from Latin solidare "to make solid," from solidus "solid" (see solid (adj.)).\n

\nModern form in English is a re-Latinization from early 15c. The loss of Latin -l- in that position on the way to Old French is regular, as poudre from pulverem, cou from collum, chaud from calidus. The -l- typically is sounded in British English but not in American, according to OED, but Fowler wrote that solder without the "l" was "The only pronunciation I have ever heard, except from the half-educated to whom spelling is a final court of appeal ..." and was baffled by the OED's statement that it was American. Related: Soldered; soldering. The noun is first attested late 14c.

n. Any of various alloys, often of tin and lead, that are used to join small pieces of metal together vb. To join with (or as if with) solder.

1. n. an alloy (usually of lead and tin) used when melted to join two metal surfaces

2. v. join or fuse with solder; "solder these two pipes together"

Solder (, or in North America ) is a fusible metal alloy used to create a permanent bond between metal workpieces. The word solder comes from the Middle English word soudur, via Old French solduree and soulder, from the Latin solidare, meaning "to make solid". In fact, solder must be melted in order to adhere to and connect the pieces together, so a suitable alloy for use as solder will have a lower melting point than the pieces it is intended to join. Whenever possible, the solder should also be resistant to oxidative and corrosive effects that would degrade the joint over time. Solders intended for use in making electrical connections between electronic components also usually have favorable electrical characteristics.

Soft solder typically has a melting point range of , and is commonly used in electronics, plumbing, and sheet metal work. Manual soldering uses a soldering iron or soldering gun. Alloys that melt between are the most commonly used. Soldering performed using alloys with a melting point above is called 'hard soldering', 'silver soldering', or brazing.

In specific proportions, some alloys can become eutectic — that is, their melting point is the same as their freezing point. Non-eutectic alloys have markedly different solidus and liquidus temperatures, and within that range they exist as a paste of solid particles in a melt of the lower-melting phase. In electrical work, if the joint is disturbed in the pasty state before it has solidified totally, a poor electrical connection may result; use of eutectic solder reduces this problem. The pasty state of a non-eutectic solder can be exploited in plumbing as it allows molding of the solder during cooling, e.g. for ensuring watertight joint of pipes, resulting in a so-called 'wiped joint'.

For electrical and electronics work, solder wire is available in a range of thicknesses for hand-soldering, and with cores containing flux. It is also available as a paste or as a preformed foil shaped to match the workpiece, more suitable for mechanized mass-production. Alloys of lead and tin were universally used in the past, and are still available; they are particularly convenient for hand-soldering. Lead-free solders are somewhat less convenient for hand-soldering due to their generally higher melting points and tendency to dissolve copper wire, but have been increasing in use due to the environmental benefits of avoiding lead-based electronic components.

Plumbers often use bars of solder, much thicker than the wire used for electrical applications. Jewelers often use solder in thin sheets, which they cut into snippets.