Semi-finished casting products are intermediate

casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...

s 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-fi ...

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 Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it a wood-like "grain" ...

, 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, blooms are intermediate-stage pieces of steel produced by a first pass of

rolling Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact ...

(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, 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 Continuous casting, also called strand casting, is the process whereby molten metal is solidified into a "semifinished" billet, bloom, or slab for subsequent rolling in the finishing mills. Prior to the introduction of continuous casting in the ...

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

drawing Drawing is a visual art that uses an instrument to mark paper or another two-dimensional surface. The instruments used to make a drawing are pencils, crayons, pens with inks, brushes with paints, or combinations of these, and in more mod ...

. Final products include

bar stock Bar stock, also (colloquially) known as blank, slug or billet, is a common form of raw purified metal, used by industry to manufacture metal parts and products. Bar stock is available in a variety of extrusion shapes and lengths. The most comm ...

and

wire Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible strand of metal. Wire is co ...

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

or indirectly by rolling an ingot on a slabbing mill. Slabs are usually further processed via flat rolling,

skelp Skelp (sometimes spelled scelp) is wrought iron or steel that is rolled or forged into narrow strips and ready to be made into pipe or tubing by being bent (into a cylindrical shape) and welded. The word is most commonly used in the tradition ...

ing, and pipe rolling. Common final products include

sheet metal Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Thicknesses can vary significantly; ex ...

, plates, strip metal,

pipes Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circul ...

, 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 p ...

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