The language of steel
This glossary provides an introduction to the world of steel.

A material with metallic properties that is composed of two or more substances, of which at least one must be a metal.

The heat treatment process by which steel products are reheated to a suitable temperature to remove stresses from previous processing and to soften them and/or improve their machinability and cold forming properties.

Apparent steel use (ASU)
ASU is obtained by adding up deliveries (defined as what comes out of the steel producer’s facility gate) and net direct imports. As a unit of measurement worldsteel uses the metric tonne.

A finished steel product, commonly in flat, square, round or hexagonal shapes. Rolled from billets, bars are produced in two major types: merchant and special.

Basic oxygen steelmaking
Making steel through oxidation by injecting oxygen through a lance above a molten mixture of pig iron and scrap steel.

Bessemer process
A process for making steel by blowing air into molten pig iron through the bottom of a converter.

A semi-finished steel product with a square cross section up to 155mm x 155mm. This product is either rolled or continuously cast and is then transformed by rolling to obtain finished products like wire rod, merchant bars and other sections. The range of semi-finished products above 155 mm x 155 mm are called blooms.

Steel sheet of high dimensional precision, in simple or complex form, sometimes multi-thickness, constituting principally automobile body parts.

Blast furnace
A furnace used for smelting iron from iron ore.

See billet

Carbon steel
A type of steel of which the main alloying element is carbon.

Increasing the carbon content of steel by diffusing carbon into the surface, allowing the surface to be heat-treated to become a hard, wear resistant layer.

An object formed by using a mould.

The primary fuel used by integrated iron and steel producers.

Applying a protective layer to the outside of a material using various methods such as galvanising.

A finished steel product such as sheet or strip which has been wound or coiled after rolling.

A form of carbonised coal burned in blast furnaces to reduce iron ore pellets or other iron-bearing materials iron.

Coke ovens
Ovens where coke is produced. Coal is usually dropped into the ovens through openings in the roof, and heated by gas burning in flues in the walls within the coke oven battery. After heating for about 18 hours, the end doors are removed and a ram pushes the coke into a quenching car for cooling before delivery to the blast furnace.

Cold rolling
Passing a sheet or strip that has previously been hot rolled and picked through cold rolls (below the softening temperature of the metal). Cold rolling makes a product that is thinner, smoother and stronger than can be made by hot rolling alone.

Continuous casting
A process for solidifying steel in the form of a continuous strand rather than individual ingots. Molten steel is poured into open-bottomed, water-cooled moulds. As the molten steel passes through the mould, the outer shell solidifies.

Cold rolled coil (see cold rolling)

Crude steel
Steel in the first solid state after melting, suitable for further processing or for sale. Synonymous with raw steel.

Direct reduction
A group of processes for making iron from ore without exceeding the melting temperature. No blast furnace is needed.

Electric arc furnace
A furnace that melts steel scrap using the heat generated by a high power electric arc. During the melting process, elements are added to achieve the correct chemistry and oxygen is blown into the furnace to purify the steel.

Electrical steels
Specially manufactured cold rolled sheet and strip containing silicon, processed to develop definite magnetic characteristics for use by the electrical industry.

Flat products
A type of finished rolled steel product like steel strip and plate.

Hot dip galvanisation
A process by which steel is given long-term corrosion protection by coating it with molten zinc.

Hot and cold rolling mill
Hot-rolling mill: Equipment on which solidified steel preheated to a high temperature is continuously rolled between two rotating cylinders.
Cold rolling mill: Equipment that reduces the thickness of flat steel products by rolling the metal between alloy steel cylinders at room temperature.

Hot metal
Molten iron produced in the blast furnace.

Hot rolled coil (see hot rolling)

A metal block cast in a particular shape for convenient further processing.

In-line strip production (ISP)
ISP produces hot-rolled coil down to finished gauges of 1mm, and has its origins in joint development work by Arvedi with German plant maker Mannesmann Demag in the late 1980s.

Integrated mill
Large-scale plant combining iron smelting and steelmaking facilities, usually based on basic oxygen furnace. May also include systems for turning steel into finished products.

Iron ore
The primary raw material in the manufacture of steel.

Ladle metallurgy
The process whereby conditions (temperature, pressure and chemistry) are controlled within the ladle of the steelmaking furnace to improve productivity in preceding and subsequent steps, as well as the quality of the final product.

Used by the steel industry to remove impurities from the iron made in blast furnaces. Limestone containing magnesium, called dolomite, is also sometimes used in the purifying process.

Line pipe
Used for transportation of gas, oil or water generally in a pipeline or utility distribution system.

Long products
A type of finished rolled steel product like rail and steel bars.

Lost time injury
Any work-related injury, resulting in the company, contractor or third party contractor employee not being able to return to work for their next scheduled work period. Returning to work with work restrictions does not constitute a lost time injury status, no matter how minimal or severe the restrictions, provided it is at the employee’s next scheduled shift. Lost Time Injury Frequency Rate (LTIFR) is calculated as number of Lost Time Injuries per million man hours.

Mechanical tubing
Welded or seamless tubing produced in a large number of shapes to closer tolerances than other pipe.

Mini mill
A small-scale steelmaking plant based on the EAF, making new steel from mostly steel scrap. May also include facilities for producing finished steel products.

Net ton
See ton

Oil country tubular goods (OCTG)
Pipe used in wells in oil and gas industries, consisting of casing, tubing and drill pipe. Casing is the structural retainer for the walls; tubing is used within casing oil wells to convey oil to ground level; drill pipe is used to transmit power to a rotary drilling tool below ground level.

Open hearth process
A process for making steel from molten iron and scrap. The open hearth furnace has a shallow hearth and roof that help to remove impurities from the molten iron. The flame and gases pass across the top of the enclosed hearth, heat being reflected down onto the material in the hearth. This process has been replaced by the basic oxygen process in most modern facilities.

An enriched form of iron ore shaped into small balls.

Using chemicals to remove the scale from finished steel.

Pig Iron
The product that results from smelting iron ore with a high-carbon fuel such as coke

A flat rolled product from slabs or ingots of greater thickness than sheet or strip.

Rebar steel
A reinforcing steel bar

Refining stand
A stage in the process of making crude steel, during which the crude steel is further refined (i.e. most residual impurities are removed) and additions of other metals may be made before it is cast.

Rolling mill
Equipment that reduces and transforms the shape of semi-finished or intermediate steel products by passing the material through a gap between rolls that is smaller than the entering materials.

Semi-finished products
Steel products such as billet, blooms and slabs. These products can be made by direct continuous casting of hot steel or by pouring the liquid steel into ingots, which are then hot rolled into semi-finished products.

A flat rolled product over 12 inches in width and of less thickness than plate.

Sheet piling
Rolled sections with interlocking joints (continuous throughout the entire length of the piece) on each edge to permit being driven edge-to-edge to form continuous walls for retaining earth or water.

Sinter plant
A plant in which iron ore is crushed, homogenised and mixed with limestone and coke breeze and then cooked (“sintered”) to form sinter which is the main ferrous component of blast furnace burden.

A process which combines ores too fine for efficient blast furnace use with flux stone. The mixture is heated to form clumps, which allow better draft in the blast furnace.

A semi-finished steel product obtained by rolling ingots on a rolling mill or processed through a continuous caster and cut into various lengths. The slab has a rectangular cross section and is used as a starting material in the production process of flat products, i.e. hot rolled coils or plates.

A by-product, containing inert materials from the ‘burden’ (the materials put into the blast furnace at the beginning of the steel making process), that is produced during the melting process.

Sponge iron
The product of the direct reduction process. Also known as direct reduced iron (DRI).

Stainless steels
Stainless steels are distinguished from carbon steel by their chromium (ferritic steel) content and, in certain cases, nickel (austenitic steel). Adding chromium to carbon steel makes it more rust and stain-resistant, and when nickel is added to chromium stainless steel it enhances its mechanical properties, for example its density, heat capacity and strength.

Standard pipe
Used for low-pressure conveyance of air, steam, gas, water, oil or other fluids and for mechanical applications. Used primarily in machinery, buildings, sprinkler systems, irrigation systems, and water wells rather than in pipelines or distribution systems.

Flat steel coil products, with widths of less than 600mm for hot rolled products and less than 500mm for cold rolled products. The wider flat products are called wide strips.

Structural pipe and tubing
Welded or seamless pipe and tubing generally used for structural or load-bearing purposes above-ground by the construction industry, as well as for structural members in ships, trucks, and farm equipment.

Structural shapes
Rolled flange sections, sections welded from plates, and special sections with at least one dimension of their cross-section three inches or greater. Included are angles, beams, channels, tees and zeds.

Thin strip continuous casting
Casting technology that takes liquid steel and casts it into solid strip in one step, thereby eliminating the need for a continuous slab caster and hot strip mill.

Tin coated steel
Cold rolled sheet, strip or plate coated with tin or chromium.

Ton (t)
1. A unit of weight in the US Customary System equal to 2,240 pounds. Also known as long ton.
2. A unit of weight in the US Customary System equal to 2,000 pounds. Also known as short ton. Also known as net ton.

Tonne (T)
A metric tonne, equivalent to 1,000 kilograms or 2,204.6 pounds or 1.1023 short ton.

True Steel Use (TSU)
TSU is obtained by adding net indirect imports to Apparent Steel Use (ASU).

Wire rods
Coiled bars of up to 18.5 millimeters in diameter, used mainly in the production of wire.

Wire: drawn and/or rolled
The broad range of products produced by cold reducing hot-rolled steel through a die, series of dies, or through rolls to improve surface finish, dimensional accuracy and physical properties.

Joining two pieces of metal together using heat and pressure to soften the materials.

Wrought iron
Low-carbon content iron that is tough and malleable for forging and welding.

Worldsteel Association: