Semi-finished casting products are intermediate castings produced in a

steel mill A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finish ...

that need further processing before being

finished goods Finished goods are goods that have completed the manufacturing process but have not yet been sold or distributed to the end user. Manufacturing Manufacturing has three classes of inventory: # Raw material # Work in process # Finished goods A ...

. There are four types: ''ingots'', ''blooms'', ''billets'', and ''slabs''.

Ingot

Ingots are large rough castings designed for storage and transportation. The shape usually resembles a rectangle or square with generous fillets. They are tapered, usually with the big-end-down.

Bloom

In the era of commercial wrought iron, blooms were slag-riddled iron castings poured in a

bloomery A bloomery is a type of metallurgical furnace once used widely for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. Bloomeries produce a porous mass of iron and slag called a ''bloom ...

before being worked into wrought iron. In the era of commercial

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

, blooms are intermediate-stage pieces of steel produced by a first pass of rolling (in a blooming mill) that works the ingots down to a smaller cross-sectional area, but still greater than . Blooms are usually further processed via rotary piercing, structural shape rolling and profile rolling. Common final products include

structural shapes Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a Profile (engineering), profile of a specific cross section (geometry ...

, rails, rods, and seamless pipes.

Billet

A billet is a length of metal that has a round or square cross-section, with an area less than . Billets are created directly via continuous casting or extrusion or indirectly via

hot rolling In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simil ...

an ingot or bloom. Billets are further processed via profile rolling and

drawing Drawing is a form of visual art in which an artist uses instruments to mark paper or other two-dimensional surface. Drawing instruments include graphite pencils, pen and ink, various kinds of paints, inked brushes, colored pencils, crayons, ...

. Final products include bar stock and wire.

Centrifugal casting Centrifugal casting is a metallurgical manufacturing process by casting that may refer to either: * Centrifugal casting (industrial), on an industrial scale * Centrifugal casting (silversmithing), for a smaller scale See also: Spin casting Sp ...

is also used to produce short circular tubes as billets, usually to achieve a precise metallurgical structure. They are commonly used as cylinder sleeves where the inner and outer diameters are

ground Ground may refer to: Geology * Land, the surface of the Earth not covered by water * Soil, a mixture of clay, sand and organic matter present on the surface of the Earth Electricity * Ground (electricity), the reference point in an electrical c ...

and machined to length. Because their size is not modified significantly, they are not always classified as semi-finished casting products. In copper production, a billet is a long, about diameter, of pure copper.

Slab

A slab is a length of metal that is rectangular in cross-section. The slab is created directly by continuous casting or indirectly by rolling an ingot on a slabbing mill. Slabs are usually further processed via flat rolling, skelping, and pipe rolling. Common final products include sheet metal, plates, strip metal, pipes, and tubes. Slab are mainly produced through

blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric ...

route. One of the reasons to preferably produce slab through BF route is to achieve high quality. Global Steel Slab Market Outlook
''Commodity Inside''. 16-08-2018. File:CC-OXY.jpg, An oxygen gas torch cutting a slab File:Slabs stack.jpg, Steel slabs

References

{{reflist Casting (manufacturing) Metalworking terminology