Annealing
The process of heating steel and then cooling it slowly at a set rate to produce the desired strength and formability.

Baghouse
An air pollution control device used to trap particles by filtering gas streams through large cloth or fiberglass bags.

Basic Oxygen Furnace (BOF)
The chief method of producing steel. Molten iron from the blast furnace is combined with steel scrap in the BOF. Pure oxygen is blown into the furnace at high velocity to speed combustion and refine the iron and scrap.

Billet
A semi-finished steel product that has been rolled or forged from an ingot or strand cast. It is smaller and longer than a bloom, usually a square cross section less than 36 square inches. Bars, pipes, wire and wire products are made from billets.

Blast furnace
The furnace used to produce iron. Iron ore, coke and limestone are heated to temperatures in excess of 3,000° F by blasts of hot air. The coke burns, emitting gases that reduce the ore to metallic iron. The limestone combines with impurities and forms slag.

Bloom
A semi-finished steel product that has been rolled or forged from an ingot or strand cast. It usually has a square cross section exceeding 36 square inches. Blooms are frequently used in the manufacture of building beams and columns.

Clarifier
A settling tank where solids are mechanically removed from waste water.

Cold drawing
The process of reducing the cross-sectional diameter of tubes or wire by drawing them through dies without heating the material.

Cold rolling
After hot rolling, annealing and pickling, coils are cold rolled to reduce them to the proper thickness for sale or additional processing.

Continuous casting
A faster method of making steel than traditional methods. A caster accepts molten steel from the basic oxygen furnace and casts it into slabs, blooms or billets, which are then sent to a finishing mill. The caster eliminates the need to pour liquid steel into ingots and can literally accept pours on a continuous basis.

Cooling towers
They are used to reduce the temperature of water that is used in processing iron and steel products.

Cupping
The process of forming tubular- or closed-cylindrical products from a flat plate. The plate is heated prior to forming.

Electric arc furnace (EAF)
A method of producing steel to exact specifications. Steel scrap, limestone and other additives are placed in the furnace. Three carbon electrodes are lowered into the furnace until they meet the cold scrap. Electric arcs then produce intense heat, transforming the scrap into molten steel.

Hot extrusion
The forming of material of continuous cross section by forcing it through a die in a press.

Hot rolling
The process of reheating slabs, billets or blooms and running them through a series of hot mills, where they are reduced to an intermediate thickness and then coiled.

Ingot
Metal that is cast into a mold, weighing as much as 30 tons. Molten steel is poured from a ladle into an ingot mold. Once it hardens, the steel is rolled or forged into a bloom, billet or slab.

Integrated
A term used to describe a steel producer that has ironmaking and steelmaking capabilities as well as the ability to process steel into finished products. An integrated producer typically operates a blast furnace to make iron and has casting, rolling and other equipment to make semi-finished and finished steel products.

Mandrel
A shaft on which steel that has been previously bored is mounted for turning and milling. It also can be a rod that is used to retain the cavity in hollow metal products during further processing.

Pickling
The process of chemically removing scale or oxide from metal products to obtain a clean surface.

Piercing
The process used to make seamless pipe and tubing from semi-finished products, called tube rounds.

Pig iron
A metallic product from the blast furnace containing more than 90 percent iron. It is used directly in the manufacture of steel. The term arose from the old-fashioned method of casting blast-furnace iron into molds that resembled a litter of suckling pigs.

Planishing
Production of a superior finish on a previously rolled or forged product, accomplished by passing the steel bar or other product through chill cast or hardened steel rolls or by hammering with a smooth-faced hammer.

Reversing mill
Rolling mill designed so the direction the rolls are turning can be reversed following each pass of the steel. This rotation can be repeated until the desired reduction is attained.

Roughing stand
Mill used for preliminary rolling.

Skelp
Steel sheet or plate from which welded tubing or pipe is made.

Slab
A semi-finished steel product that is hot-rolled down from an ingot or strand cast. It is wide and rectangular in shape. Slabs are used in the manufacture of sheets, strip, plates and other flat-rolled steel products.

Strand casting
This method uses a caster machine. Molten steel is transferred from a ladle into a reservoir, called a tundish. From there, the steel flows into molds of a continuous casting machine. As the metal is water cooled, it solidifies into one long strand and then is cut to length by torches.