Designation for Foiled Twisted Quad Cable. This cable type has two individual groups of four twisted conductors covered by a foil shield.

A cell that can continuously convert chemical energy to electrical energy.

See Annealing, Full.

One made of single material as opposed to one of a mixture of materials.

A characteristic of a network protocol in which there may be simultaneous data transmission in both directions and on multiple pairs in a cabling system.

A temper corresponding approximately to a cold-worked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following full annealing.

A method of removing fumes that is especially necessary in the pick­ling shop to give proper working conditions and to prevent structural corrosion. Systems can be: lip-type, where fumes are extracted by trunking, which rests on the sides or lip of the bath or baths and does not interfere with the entry or removal of the work from the bath; by fans placed above and to one side of the tank to form an invisible barrier of clean air; and by completely enclosing the cleaning line in what is vir­tually a building within the main building.

The ability of a conductor or cable assembly to resist physical or electrical degradation caused by fungus growth in wet or damp environments.

A flared or widened entrance to a terminal or connector wire barrel. This permits easier insertion of the conductor, and helps assure that all wire strands will be directed into the wire barrel.

An enclosure in which heat is generated or enters from another heat source. This is generally done through combusting a fuel or by converting electricity to heat. In the wire industry, furnaces are typically used to increase the workability before and/or after drawing or rolling, as well as to impart other properties desirable in the end product.

Gas that surrounds the material in a furnace. Generally, an atmosphere is supplied to protect the material against damage that would result if heated in ambient air. For ferrous wire, atmospheres protect against oxidation and decarburization. Some atmospheres are “inert,” protecting the material by displacing air (e.g., nitrogen). Other atmospheres are “reactive,” protecting the material by chemically reacting with the air (e.g., hydrogen). In practice, furnace atmospheres tend to be a mixture of inert and reactive components. These gas mixtures are either delivered separately in bulk and then mixed, or are generated at the site of the furnace. See Controlled Atmosphere.

One of two major facilities (the other being an electric arc furnace) used to produce liquid steel. A jet of high-velocity oxygen impinges on the metal and reacts with carbon and other impurities to form liquid steel. The product is tapped into a ladle and may be ladle-refined. It is subsequently strand cast directly into blooms or billets, or teemed into ingots for further working. The design is known as the Linz-Donawitz Process (see entry).

A furnace in which one complete group of material is placed in the furnace, heated (and may have some other treatment) and removed before the next group is positioned in place.

A type of mobile batch furnace that is cylindrically shaped and moved from load to load with a crane. The material is placed on a fixed hearth or “base” and then covered with a retort or “inner cover” to provide a gas-tight chamber for the furnace atmosphere. The bell furnace is then placed onto the base over the inner cover. Bell furnace systems use a convection fan that is located in the base below the material. A “forced cooler” may be placed over the inner cover to reduce the temperature to a level that will not discolor the material when exposed to air.

A furnace in which material is continuously fed. For the wire industry, the material can be fed without unwinding the coil (e.g. as in a pusher-type furnace). Or, the material can be fed by unwinding one or more coils and pulling the individual strands through.

One of two major types of facilities used to produce liquid steel (the other being a Basic Oxygen Furnace). The furnace uses electrical resistance or induction to form molten steel. The product is tapped into a ladle, subsequently strand cast directly into blooms or billets, or teemed into ingots for further working.

A furnace in which convection is the most significant means of heat transfer. Also known as “convection furnaces,” such furnaces typically have some sort of fan to circulate the cold gas across the heat source and into the chamber containing the material to be heated.

A furnace whose heat is obtained from electrical current flow in the material to be heated. Alternating current in induction coils that surround, but do not touch the material, cause a second­ary current to flow in that material. The secondary electrical current generates heat in the material based on the electrical resistance characteristics of the material.

A furnace for melting metal in which the bath is heated by the convection of hot gases over the surface of the metal and by radiation from the roof. Until the second half of the 20th century, most of the world steel was produced in the open-hearth furnace. By the middle of the 20th century, the open-hearth process was surpassed by other technologies. The last open-hearth furnaces in North America were bricked up in the 1980s.

A furnace in which the material is either indexed or continuously moved through-force applied at the entry-end. Typically, the material is loaded onto some form of conveyance (e.g., trays with rollers), and then is pushed through the furnace to exit at the opposite end.