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Casting is the process of production of objects by pouring molten material into a cavity called a mould which is the negative of the object, and allowing it to cool and solidify. Sand casting is a means of producing rough metal castings using a mould usually made from sand formed around a replica of the object to be cast that is removed once the sand has been compacted. Sand castings not further worked by polishing or peening are readily recognized by the sand-like texture imparted by the mould. As the accuracy of the casting is limited by imperfections in the mould-making process there will be extra material to be removed by grinding or machining, more than is required by other more accurate casting processes. Furthermore, because the mould is destroyed in order to retrieve the object, a new mould must be made for each casting. Image File history File links Broom_icon. ... Image File history File links No higher resolution available. ... This article is about the manufacturing process. ...

Patterns

From the design, provided by an engineer or designer, a skilled patternmaker builds a pattern of the object to be produced, using wood, metal, or plastic; other materials to be used can be polystyrene or even sand strickled into shape. The metal to be cast will contract during solidification, and this may be non-uniform due to uneven cooling. Therefore, the pattern must be slightly larger than the finished product, a difference known as contraction allowance. Patternmakers are able to produce suitable patterns using 'Contraction rules'. Different scaled rules are used for different metals because different metals / alloys contract at different rates. Patterns also have coreprints; these create registers within the molds, into which are placed Sand cores. Sand cores are used to create under cut profiles and holes which cannot be molded. The top and bottom halves of a sand casting mould showing the cavity prepared by patterns. ...

Paths for the entrance of metal, during the pouring (casting) process into the mold cavity constitute the runner system and include the sprue, various feeders which maintain a good metal 'feed' and 'runners', and ingates which attach the runner system to the casting cavity. Gas and steam generated during casting exit through the permeable sand or via the riser, are added either in the pattern itself, or as separate pieces. Bronze casting showing sprue and risers In foundry work, a Sprue is the passage through which metal is poured into a mold. ... A riser is a reservoir built into a metal-casting mold to prevent cavities due to shrinkage. ...

Cope & drag (top and bottom halves of a sand mold), with cores in place on the drag

Download high resolution version (2019x1362, 326 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2019x1362, 326 KB) Wikipedia does not have an article with this exact name. ...

Molding box and materials

A multi-part molding box (known as a casting flask, the top and bottom halves of which are known respectively as the cope and drag) is prepared to receive the pattern. Molding boxes are made in segments that may be latched to each other and to end closures. For a simple object—flat on one side—the lower portion of the box, closed at the bottom, will be filled with prepared casting sand or green sand—a slightly moist mixture of sand and clay. The sand is packed in through a vibratory process called ramming and, in this case, periodically screeded level. The surface of the sand may then be stabilized with a sizing compound. The pattern is placed on the sand and another molding box segment is added. Additional sand is rammed over and around the pattern. Finally a cover is placed on the box and it is turned and unlatched, so that the halves of the mold may be parted and the pattern with its sprue and vent patterns removed. Additional sizing may be added and any defects introduced by the removal of the pattern are corrected. The box is closed again. This forms a "green" mold which must be dried to receive the hot metal. If the mold is not sufficiently dried a steam explosion can occur that can throw molten metal about. In some cases, the sand may be oiled instead of moistened, which makes possible casting without waiting for the sand to dry. Sand may also be bonded by chemical binders, such as furane resins or amine-hardened resins. A Casting Flask is a wooden or metal frame, used in a foundry to contain molding sand used to make a mold. ... In foundry work, the terms Cope and Drag refer to the upper and lower parts of a two-part casting flask, used in sand casting. ... Molding Sand, or Foundry sand, is sand that when moistened or oiled tends to pack well and hold its shape. ... Description Green Sand is an aggregate of sand, bentonite clay, and water. ...

Chills

If it is desired to have most of the—iron or steel—casting in a tough, ductile, state but with a few surfaces hard, it is possible to place metal plates—chills— in the mold, where the metal is to be hardened. The associated rapid local cooling will form a finer-grained and harder metal at these locations. The effect is similar to quenching metals in forge work. The inner diameter of an engine cylinder is made hard by a chilling core. A Chill is an object used in making metal castings. ... A quench refers to a rapid cooling. ... For finery forges (making iron), see finery forge. ...

Cores

To produce cavities within the casting—such as for liquid cooling in engine blocks and cylinder heads—negative forms are used to produce cores. Usually sand-molded, cores are inserted into the casting box after removal of the pattern. Whenever possible, designs are made that avoid the use of cores, due to the additional set-up time and thus greater cost. The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. ... The cylinder head from a GMC van. ...

Two sets of castings (bronze and aluminium) from the above sand mold

With a completed mold at the appropriate moisture content, the box containing the sand mold is then positioned for filling with molten metal—typically iron, steel, bronze, brass, aluminum, magnesium alloys, or various pot metal alloys, which often include lead, tin, and zinc. After filling with liquid metal the box is set aside until the metal is sufficiently cool to be strong. The sand is then removed revealing a rough casting that, in the case of iron or steel, may still be glowing red. When casting with metals like iron or lead, which are significantly heavier than the casting sand, the casting flask is often covered with a heavy plate to prevent a problem known as floating the mold. Floating the mold occurs when the pressure of the metal pushes the sand above the mold cavity out of shape, causing the casting to fail. Download high resolution version (1932x1149, 289 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1932x1149, 289 KB) Wikipedia does not have an article with this exact name. ... For other uses, see Iron (disambiguation). ... For other uses, see Steel (disambiguation). ... Assorted ancient Bronze castings found as part of a cache, probably intended for recycling. ... For other uses, see Brass (disambiguation). ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... An alloy of copper and lead. ... For Pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series Post-transition metals or poor metals Group, Period, Block 14, 6, p Appearance bluish gray Standard atomic weight 207. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Standard atomic weight 118. ... General Name, symbol, number zinc, Zn, 30 Chemical series transition metals Group, period, block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ...

Left:- Corebox, with resulting (wire reinforced) cores directly below. Right:- Pattern (used with the core) and the resulting casting below (the wires are from the remains of the core)

After casting, the cores are broken up by rods or shot and removed from the casting. The metal from the sprue and risers is cut from the rough casting. Various heat treatments may be applied to relieve stresses from the initial cooling and to add hardness—in the case of steel or iron, by quenching in water or oil. The casting may be further strengthened by surface compression treatment—like shot peening—that adds resistance to tensile cracking and smooths the rough surface. Download high resolution version (1860x1299, 246 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1860x1299, 246 KB) Wikipedia does not have an article with this exact name. ... Heat treatment is a method used to alter the physical, and sometimes chemical, properties of a material. ... Shot peening is a process used to produce a decorative finish and to modify mechanical properties of metals. ...

Design requirements

The part to be made and its pattern must be designed to accommodate each stage of the process, as it must be possible to remove the pattern without disturbing the molding sand and to have proper locations to receive and position the cores. A slight taper, known as draft, must be used on surfaces perpendicular to the parting line, in order to be able to remove the pattern from the mold. This requirement also applies to cores, as they must be removed from the core box in which they are formed. The sprue and risers must be arranged to allow a proper flow of metal and gasses within the mold in order to avoid an incomplete casting. Should a piece of core or mold become dislodged it may be embedded in the final casting, forming a sand pit, which may render the casting unusable. Gas pockets can cause internal voids. These may be immediately visible or may only be revealed after extensive machining has been performed. For critical applications, or where the cost of wasted effort is a factor, non-destructive testing methods may be applied before further work is performed. A draft angle describes the amount of taper for molded or cast parts perpendicular to the parting line. ...

Decorative use of patterns

Some collectors seek obsolete hardwood patterns, once used to make molds for casting machine parts, to use as interior decorations. These are valued due to the fine woodworking involved and the display of the grain of the wood.

Alternative casting methods

Sand casting for mass production has largely been superseded by other methods.

• Modern mass production methods can produce thin but accurate molds—of a material superficially resembling paper mache, such as is used in egg cartons, but that is refractory in nature—that are then supported by some means, such as dry sand surrounded by a box, during the casting process. Due to the higher accuracy it is possible to make thinner and hence lighter castings, because extra metal need not be present to allow for variations in the molds. These thin-mold casting methods have been used since the 1960s in the manufacture of cast-iron engine blocks and cylinder heads for automotive applications.

• Various automotive mechanical components are now frequently made of aluminum, which for appropriately shaped components may be made either by sand casting or by die casting, the latter an accurate process that greatly reduces both materials use and machining and finishing costs. While the material and the processing setup is more expensive than the use of iron this is one of the most straightforward ways to reduce weight in a vehicle, important as a contributor to both fuel economy and acceleration performance. For front engine vehicles with rear wheel drive the improvement in weight distribution can improve both handling and traction. For all configurations weight saved in the engine is multiplied in that this enables use of lighter suspension components which in turn improves suspension response by reducing unsprung weight

• Starting in the early 1980s, some castings such as automotive engine blocks have been made using a sand casting technique conceptually similar to the lost wax process, known as the lost foam process. In this process, the pattern is made of polystyrene foam, which the sand is packed around, leaving the foam in place. When the metal is poured into the mold, the heat of the metal vaporizes the foam a short distance away from the surface of the metal, leaving the molding cavity into which the metal flows. The lost-foam process supports the sand much better than conventional sand casting, allowing greater flexibility in the design of the cast parts, with less need for machining to finish the casting. This technique was developed for the clay mold casting of abstract art pieces and was first adopted for large quantity commercial production by the Saturn Corporation.

The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... This article is about the manufacturing process. ... This does not cite its references or sources. ... This article is about the manufacturing process. ... Lost foam casting (LFC), also called Evaporative Pattern Casting, is a type of investment casting process that uses foam patterns as the investment. ... Polystyrene (IPA: ) is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum by the chemical industry. ... This article does not cite any references or sources. ...

External links

• Iron casting in a hobby foundry
• Aluminum and bronze casting in a homemade foundry

Metalworking:
Casting: Image File history File links This is a lossless scalable vector image. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ...	Casting Technologies | Sand | Lost Foam | Investment (Lost Wax) | Die | Spin | Shaw process | Centrifugal | Tilt | Vacuum | Continuous | Billet This article is about the manufacturing process. ... Lost foam casting (LFC) is a type of investment casting process that uses foam patterns as the investment. ... The lost wax process is a method that requires the metallurgist to build a wax replica of the item that is desired to be replicated, followed by the coating of the wax sculpted article in a heat resistant yet durable exterior, typically a ceramic, which is then fired to permit... This article is about the manufacturing process. ... Spin casting or Centrifugal Rubber Mold Casting (CRMC) is a method of utilizing centrifugal force to produce castings from a rubber mold. ... Centrifugal casting or rotocasting is a casting technique which has application across a wide range of industrial and artistic applications: It is used as a means of casting small, detailed parts or jewelry. ... Vacuum casting is a means of casting small metal parts or jewelry that have fine detail or for casting various plastic materials. ... Continuous casting is a refinement of the casting process for the continuous, high-volume production of metal sections with a constant cross-section. ... Billet is a term used in manufacturing to refer to a cast product. ... Furnace Technologies | Cupola | Reverberatory | Puddling | Bessemer | Open Hearth | Electric Arc | Electric Induction | Rotary A furnace is a device for heating air or any other fluid. ... A reverbatory furnace is a metallurgical or process furnace which characteristically isolates the material being processed from contact with the fuel, but not from contact with the combustion gases. ... Schematic drawing of a puddling furnace The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. ... Bessemer Converter, Schematic Diagram The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron. ... Open hearth furnaces are one of a number of kinds of furnace where excess carbon and other impurities are burnt out of pig iron to produce steel. ... An electric arc furnace is a system that heats charged material by means of an electric arc. ... An induction furnace, with fume hood closed, tapping a melt An induction furnace is an electrical furnace in which the heat is applied by induction heating of a conductive medium (usually a metal) in a crucible around which water-cooled magnetic coils are wound. ... Casting Terminology | Flask | Sprue | Riser | Cope and drag | Draft angle | Dross | Green sand | Molding sand | Chill | Ingot | Pattern | Slag A Casting Flask is a wooden or metal frame, used in a foundry to contain molding sand used to make a mold. ... Bronze casting showing sprue and risers In foundry work, a Sprue is the passage through which metal is poured into a mold. ... A riser is a reservoir built into a metal-casting mold to prevent cavities due to shrinkage. ... In foundry work, the terms Cope and Drag refer to the upper and lower parts of a two-part casting flask, used in sand casting. ... A draft angle describes the amount of taper for molded or cast parts perpendicular to the parting line. ... Dross is a mass of solid impurities floating on a molten metal bath. ... Description Green Sand is an aggregate of sand, bentonite clay, and water. ... Molding Sand, or Foundry sand, is sand that when moistened or oiled tends to pack well and hold its shape. ... A Chill is an object used in making metal castings. ... [[Image:[[Gold bars|Gold ingots. ... The top and bottom halves of a sand casting mould showing the cavity prepared by patterns. ... Slag is also an early play by David Hare. ...
Jewellery making:	Casting | Centrifugal casting | Cloisonné | Doming technique | Draw plate | Engraving | Filigree | Findings | Fretwork | Goldwork | Lapidary | Metal clay | Millesimal fineness | Omega chain | Persian weave | Relief | Repoussé and chasing | Soldering | Vacuum casting | Water torch | Wire wrap jewellery This article is about the manufacturing process. ... Centrifugal casting or rotocasting is a casting technique which has application across a wide range of industrial and artistic applications: It is used as a means of casting small, detailed parts or jewelry. ... Cloisonné is a multi-step enamel process used to produce jewelry, vases, and other decorative items. ... doming blocks and punch The technique of doming (or dapping) is used to make spheres or hemispheres of metal. ... Draw plate front Draw plate back Draw plate top edge Draw plates are used to draw wire to make it thinner. ... Engraving is the practice of incising a design onto a hard, flat surface, by cutting grooves into it. ... Filigree (formerly written filigrann or filigrane) is a jewel work of a delicate kind made with twisted threads usually of gold and silver. ... Findings refers to jewellery components used to put together the jewelry. ... Fretwork is an interlaced decorative design that is either carved in low relief on a solid background, or cut out with a fretsaw, jigsaw or scrollsaw. ... Goldwork is a type of metalwork particularly concerned with gold and its use in jewellery and coinage. ... A lapidary (the word means concerned with stones) is an artisan who practices the craft of working, forming and finishing stone, mineral, gemstones, and other suitably durable materials (amber, shell, jet, pearl, copal, coral, horn and bone, glass and other synthetics) into functional and/or decorative, even wearable, items (e. ... Metal clay, is a clay-like medium used to make jewelry, beads and small sculpture, consists of very small particles of precious metals (such as silver, gold or platinum) mixed with an organic binder and water. ... Millesimal fineness is a system of denoting the purity of platinum, gold and silver alloys by parts per thousand of pure metal in the alloy. ... An Omega chain is a pseudo-chain made by assembling metallic links on a wire or woven mesh. ... Persian weave is a methode of weave used in jewelry and other art forms. ... In the art of sculpture, a relief is an artwork where a modelled form projects out of a flat background. ... Repoussé bracelet by Thomas Feeser, ©2005. ... (De)soldering a contact from a wire. ... Vacuum casting is a means of casting small metal parts or jewelry that have fine detail or for casting various plastic materials. ... A water torch, sometimes called a water welder, is a device that produces a high-temperature directed flame and is used for precision welding, brazing, and cutting of metals typically employed in the making of jewelry,electronics boards and parts, and fiber optic applications. ... Wire wrap jewellery is a type of design and method of hand jewellery fabrication. ...
Metalworking topics:   Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ...	Casting | CNC | Cutting tools | Drilling and threading | Fabrication | Finishing | Grinding | Jewellery | Lathe (tool) | Machining | Machine tooling | Measuring | Metalworking | Hand tools | Metallurgy | Milling | Occupations | Press tools | Smithing | Terminology | Welding This article is about the manufacturing process. ... A CNC Turning Center A CNC Milling Machine The abbreviation CNC stands for computer numerical control, and refers specifically to a computer controller that reads G-code instructions and drives the machine tool, a powered mechanical device typically used to fabricate metal components by the selective removal of metal. ... a Cutting Tool, in the context of Metalworking is any tool that is used to remove metal from the workpiece by means of shear deformation. ... Drilling is the process of using a drill bit in a drill to produce holes. ... A typical steel fabrication shop Fabrication, when used as an industrial term, applies to the building of machines , structures, process equipment for chemical, fertilizer sector by cutting, shaping and assembling components made from raw materials. ... Metalworking finishing is the activity of making things out of metal in a skillful manner. ... Rotating abrasive wheel on a bench grinder. ... Amber jewellery in the form of pendants Jewellery (also spelled jewelry, see spelling differences) is a personal ornament, such as a necklace, ring, or bracelet, made from jewels, precious metals or other substance. ... Conventional metalworking lathe In woodturning, metalworking, metal spinning, and glassworking, a lathe is a machine tool which spins a block of material so that when abrasive, cutting, or deformation tools are applied to the block, it can be shaped to produce an object which has rotational symmetry about an axis... A lathe is a common tool used in machining. ... A machine tool is a powered mechanical device, typically used to fabricate metal components of machines by the selective removal of metal. ... The examples and perspective in this article or section may not represent a worldwide view. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ... Metalworking hand tools are hand tools that are used in the metalworking field. ... Georg Agricola, author of De re metallica, an important early book on metal extraction Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. ... Endmills for a milling machine. ... It has been suggested that this article or section be merged with Smith (metalwork). ... Power press with a fixed barrier guard A press, or a machine press is a tool used to work metal (typically steel) by changing its shape and internal structure. ... A smith, or metalsmith, is a person involved in the shaping of metal objects. ... This article needs to be wikified. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ...