Glossary of Metal Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

SCALE

Oxide of iron that forms on the surface of steel after heating.

SEAMLESS PIPE (SEAMLESS TUBE)

Tubular product made from a solid billet, which is heated, then rotated under extreme pressure. This rotational pressure creates an opening in the center of the billet, which is then shaped by a mandrel to form the pipe or tube.

SELENIUM

Chemical symbol Se. A gray metal chemically similar to tellurium; excellent conductor of electricity; obtained as a by-product of the electrolytic refining of copper; used chiefly in photoelectric cells, rectifiers, and other electronic devices, and as a pigment for glass and ceramics.

SEMI-FABRICATED

Partially processed metals shapes (sheet, plate, bar, rod, wire, extrusions; foil in the case of aluminum).

SEMI-FINISHED

First-stage metal shapes (blooms, billets or slabs) later to be rolled into semi-fabricated and, then, finished products.

SERVICE CENTER

A catchall name for an operation that buys metal, warehouses it, often processes it in some way, and then sells it in a slightly different form or amount from what was purchased from producing mills.

SHEARING

Type of cutting operation in which the metal object is cut by means of a moving blade and fixed edge or by a pair of moving blades that may be either flat or curved.

SHEET

A broad, thin (down to 5/100 of an inch), flat mass of rolled metal in widths from 24' to 80'; sold either in cut-to-length pieces or rolled into large, heavy coils.

SILICON

Chemical symbol Si. A non-metallic element, essential in the smelting of numerous ferrous and non-ferrous metals. SILICON-BRONZE-An alloy of copper and 1.5-3% silicon with various third elements (zinc, tin, or manganese).

SILICON ELECTRICAL STEEL

A type of specialty steel created by introducing silicon during the steel making process. Electrical steel exhibits certain magnetic properties, which make it optimum for use in transformers, power generators and electric motors. "Grain-oriented" product has the metal's grain running parallel within the steel, permitting easy magnetization along the length of the steel (used mostly in power transformers); "non-grain-oriented" product has no preferential direction for magnetization (used mostly in electric motors).

SILVER

Chemical symbol Ag. Brilliant, rare "precious metal" with high ductility, excellent thermal conductivity, low level of electrical resistance. Usually found as by-product of base metal ores, sometimes with gold. Historical use has been coinage, jewelry, tableware, but has major industrial applications in photography, dentistry, electronics, chemicals, and medicine manufacture.

SLAB

The most common type of semi-finished metal. In steel, semi-finished product (hot rolled from ingot or sheared from continuous caster's output) destined for further processing into strip, sheet, plate, or welded pipe product; in zinc, the primary metal casting to be rolled or forged into other shapes.

SLITTING

Cutting a sheet of metal into narrower strips to match customer needs. Because mills have limited flexibility as to the widths of the sheet that they produce, service centers or independent processors normally will cut the sheet for the customer.

SPECIAL BAR QUALITY

Arcane terminology used to describe a wide variety of higher-quality carbon and alloy bars that are used in the forging, machining and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts and valves. SBQ steel bars generally contain more alloys than merchant (commodity) grades of steel bars, and is made with more precise dimensions and chemistry.

SPECIALTY ALLOYS

Specialty metals with proprietary chemistries and designations; often made for specific high-strength or corrosive resistant applications; sometimes considered to be the low end of the various families of superalloys.

SPECIALTY STEEL

Also known as "specialty stainless steels," these are batch-produced iron-based metals with varying degrees of such additives as chrome, nickel, cobalt, titanium, manganese, copper, and molybdenum to add strength or corrosion-resistance.

SPRING STEEL

Steel strip, normally of the high-carbon or alloy type, used in the manufacture of springs because of high tensile properties.

STAINLESS STEELS

Corrosion-resistant steel of a wide variety that always contains more than 10% chromium, with or without other alloying elements. Stainless steel resists corrosion attack by organic acids, weak mineral acids, and atmospheric oxidation, keeps its strength at high temperatures, and is easily maintained. The most common grades of stainless steel are: Type 304, austenitic (chromium-nickel); Type 316, austenitic with 2%-3% molybdenum; Type 409, ferritic (low chromium) for high-temperature use; Type 410, heat-treatable martensitic (medium chromium) with a high strength level Type 430, ferritic general-purpose grade with some corrosion resistance. (See STEEL, FERRITIC, AUSTENITIC, MARTENSITIC, NICKEL-BASED SUPER ALLOYS)

STAMPING

Process of pressing with a powerful die a metal blank into a predetermined shape (or pattern). The metal used must be ductile (malleable) enough to bend into shape without breaking.

STEEL

Chemical symbol Fe. Iron smelted with carbon (more than about 0.05% and less than 2%) along with manganese, silicon, sulfur, and phosphorous. Steel is the least expensive and most widely used metal. Steel is made primarily of iron and carbon with thousands of varieties possible, depending on the content of those elements and such other alloying metals as chromium, nickel, manganese, silicon, vanadium, and molybdenum. Stainless steel is the most common of the alloy steels. (see CARBON STEEL, ALLOY STEEL, STAINLESS STEEL, SPECIALTY STEEL)

STRIP

A cold-rolled ferrous or non-ferrous metal product that is 23 15/16' and narrower; under 0.250' in thickness.

STRUCTURALS

Metal product group that includes beams and, for steel, sheet piling.

STRUCTURAL TUBING

(See HOLLOW STRUCTURAL SECTIONS)

SUPERALLOYS

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Lightweight metal alloys designed for continuous exposure to extreme heat or corrosive environments. Also called "high-performance specialty metals," the conventional superalloys are iron-based, cobalt-based, nickel-based, and titanium-based.

TANTALUM

Chemical symbol Ta. A by-product of tin processing, this refractory metal is used as a barrier to corrosion of chemical processing and carbide cutting tools, and still-growing use as electronic capacitors and filaments. Melts at 2415-degree F.

TELLURIUM

Chemical symbol Te. A brittle, silvery-white metal produced commercially as a by-product of copper smelting and maintained in the tellurium-copper alloy to aid in machining.

TEMPERING

Re-heating a quench-hardened or normalized ferrous alloy to a temperature below the transformation range and then cooling at any rate desired. In heat treatment, re-heating hardened steel to some temperature below the A1 temperature for the purpose of decreasing hardness and/or increasing toughness.

TERNE

Mixture of lead and tin.

TIN

Chemical symbol Sn. Soft, silvery-white metal with high malleability and ductility, but little tensile strength. One of the earliest metals known; because of its hardening effects on copper, used to make bronze for fabrication of construction and hunting tools and war weapons as early as 3500 B.C. With a melting point of 449-degrees F and a boiling point of 4384-degrees F, tin has the longest molten-state range of any common metal; thus, its principal use as a steel coating and constituent in alloys to make bronze, pewter, die-casting alloys, and specialty titanium alloys. Used in biocides to control insect infestation, and in solders for joining pipes or electrical conductors.

TIN MILL

Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers.

TIN/CHROME PLATING

A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area.

TIN-FREE STEEL

Chromium-coated steel. Because it is used in food cans just like tin plate, it is misclassified as a tin mill product.

TINPLATE

Sheet steel that has been coated on both sides with a very thin coating of commercial pure tin by an electro-deposition process, in which the steel is made to be the cathode (negative electrode) in an electrolytic bath containing a decomposable tin salt.

TITANIUM

Chemical symbol Ti. A bright white metal; very malleable and ductile. Its principal function has been as an alloy in steel making, but now is being used extensively (especially in aviation and aerospace) because of its high strength, lightweight, and good corrosion resistance.

TITANIUM-BASED SUPERALLOYS

Lightweight, non-corrosive alloys suitable for high-temperature applications (such as jet aircraft structural parts). Titanium alloy comes from blending with such other metals as aluminum, iron, vanadium, silicon, cobalt, tantalum, zirconium, and manganese.

TOOL & DIE STEELS

Also called "tool steel," any high carbon or alloy steel capable of being suitably tempered for use in the manufacture of tools and dies.

TRAILERLOAD, TRUCKLOAD

Quantities of commodities, including primary and secondary metals, that amount to as much as 44,000 pounds each, which is the standard weight limit on U.S. highways.

TREAD PLATE

Usually carbon (but also alloy and stainless) steel plate rolled with closed surface designs of small perforated buttons or small diamond-shaped lugs; used widely for ramps, walkways, and stairs.

TUBING

(See PIPE)

TUNGSTEN

Chemical symbol W. Gray metal with high tensile strength; ductile and malleable, immune to atmospheric influences and all acids but strong alkalis. Extremely pliable; can be drawn into filament for incandescent bulbs, rolled into thin sheet for radio tubes; ground into powder, and mixed with carbon and then embedded in soft metal (such as cobalt) to produce carbide tools, or alloyed within steel to make abrasion-resistant tool and die steels.

VANADIUM

Chemical symbol V. Vanadium is a gray metal primarily used as an alloying agent for iron and steel and as a strengthener for titanium-based alloys. Vanadium is also a catalyst in sulfuric acid production. After the steel industry, the aerospace market ranks as the second-largest end-user of the metal named for the Scandinavian love goddess Vanadis.

WIDE-FLANGE BEAM

A structural steel section on which the flanges are not tapered, but have equal thickness from the tip to the web and are at right angles to the web. Wide-flange beams are differentiated by the width of the web, which can range from 3 inches to more than 40 inches, and by the weight of the beam, measured in pounds per foot.

WIREBAR

Semi-finished form of electrolytically refined copper, designed for rolling into rod or bars and, ultimately, into strip or wire.

ZINC

Chemical symbol Zn. Bluish-white, lustrous metal derived from ores that also contain lead, silver, copper, germanium, and cadmium. Essential nutrient element in soils and animals. Pure metal is malleable and ductile even at ordinary temperature. It can be electro-deposited, and is used primarily as a galvanized protective coating for steel (especially steel destined for use in construction, transportation, and electrical equipment). Its most important alloys are brass and bronze. Of great importance in die casting, although new ZA (zinc-aluminum) alloy is becoming a major force in die-casting. Compounds and dusts used by agricultural, chemical, paint, and rubber industries.

ZINCROMETAL

A cold-rolled steel sheet product with a base coat of chromium and zinc and a top coating of a weldable zinc-rich primer.

ZIRCONIUM

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Chemical symbol Zr. A steel-gray, strong, ductile metal obtained by chemical processing of zircon-bearing sands. Minor metal has good corrosion-resistance, especially at elevated temperatures. Used in steel making, and as structural material in nuclear reactors and cladding material for uranium.