Obsolete scrap is derived from steel-containing goods at the end of their useful lives, while revert scrap is steel waste produced and recycled within a steelworks. New production scrap is generated when steel is cut and formed during the manufacturing of finished products or components.

Seamless tubes are made from solid blocks of steel that are pierced and drawn into tube shape. Seamless tubes have greater strength than welded tubes because of their homogenous microstructure, but are much more expensive to produce. They are made by rolling a preheated billet between offset rolls which is then pierced with a pointed bar or plug to create a tube shell. This is then elongated in a multi-stand rolling mill to achieve the desired thickness

Steelmakers use a secondary metallurgy vessel between the steelmaking and casting operations to allow molten steel to be brought to the required specification. Key operations can include deoxidation, desulphurisation and dephosphorisation. Not only does the use of secondary metallurgy enable a larger range of steel grades to be cast, but fine tuning steel composition in a separate furnace greatly improves the productivity of the main steelmaking unit. This is because with metallurgical adjustments taking place elsewhere, the time from steelmaking raw materials in, to tapped liquid steel out, is shortened.

Semis is short for semi-finished steel, which is the name given to large, uniform cast pieces that require further processing in order to be transformed into finished long, flat and tubular steel products.

Shredding transforms mixed metallic scrap into a more homogeneous product. It is done in a shredder, a powerful piece of enclosed equipment with rotating hammers which break down the incoming material. Shredded scrap’s regular consistency is attractive to electric arc furnace operators as it is easy to charge and offers uniform steel chemistry.

A process in which fine materials are combined into a porous mass that can be used in the blast furnace.

Semi-finished steel product - the main intermediate material in the production of flat rolled steel. Slab is usually hot rolled into plate or into hot rolled coil.

The word slag is used to describe the impurities in a molten pool of iron. It is lighter than iron, so it will float on top of the pool, where it can be skimmed.

As opposed to ordinary mild or carbon steels, special steels are alloyed to achieve particular mechanical properties to suit specific end-uses. Examples include steels for cutting tools, roller bearings or springs.

Alloy of iron, carbon and other elements with a carbon content below 1.7 percent.

This describes the amount of steel used per unit of gross domestic product. Intensity reflects the secular demand for steel, as opposed to cyclical demand. The amount of steel used in vehicles and the popularity of alternative materials affect the intensity, or how much steel is needed per unit produced. The state of the economy, however, determines the number of units.

A steel merchant who maintains a stock of steel products in a warehouse for sale in small lots to end-users. The merchant will often undertake processing work, such as slitting coil, cutting-to-length and blanking to suit the steel to particular end-uses. Also known as a steel service centre when such additional processing is undertaken.

Thin flat steel normally produced in a continuous strip and wound into a coil weighing up to 40 tonnes for further processing.

Structural steel is produced specifically for building construction with a specific shape or cross section, chemical composition and strength. These parameters and more, such as storage, are regulated to particular standards in most industrialised countries.

This is an addition to the normal mill price of steel to cover the cost of alloying elements used in producing certain grades. In some cases surcharges also reflect energy costs. Surcharges were introduced when the price of alloying elements, such as nickel, became much more volatile, moving sharply away from their historic, and more stable, price range. Mills were faced with sharply escalating prices and introduced surcharges to protect their margins. Clearly over time surcharge values move down as well as up.