NationMaster - Encyclopedia: Draft angle

A draft angle describes the amount of taper for molded or cast parts perpendicular to the parting line. One half of a bronze mold for casting a socketed spear head dated to the period 1400-1000 BC. There are no known parallels for this mold. ... This article is about the manufacturing process. ...

Consider the fabrication of a hollow plastic box, without lid. Once the plastic has hardened around the mold, the mold must be removed. As the plastic hardens, it may contract slightly. By tapering the sides of the mold by an appropriate "draft angle", the mold will be easier to remove.

If the mold is to be removed from the top, the box should taper in towards the bottom, such that measuring the bottom internal dimension will yield a smaller length and width than measuring the top from which the mold is extracted.

By specifying the opening length and width, a draft angle, and a depth, it is not necessary to specify the dimensions for the internal surface, as these may be calculated from the above.

Categories: Articles lacking sources from May 2007 | All articles lacking sources | Manufacturing | Casting Image File history File links Question_book-3. ... Image File history File links Blacksmith-hammer-anvil-50x50. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ... This article is about the manufacturing process. ... 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. ... 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. ... 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. ... 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. ... 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. ... Modern gold ingots from the Bank of Sweden An Ingot is a mass of material cast into a shape which is easy to handle. ... 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. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ... This article is about the manufacturing process. ... For other uses, see CNC (disambiguation). ... 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. ... This article is about smithing. ... Metalworking finishing is the activity of making things out of metal in a skillful manner. ... Rotating abrasive wheel on a bench grinder. ... For the Korean music group, see Jewelry (group). ... Center lathe with DRO and chuck guard. ... 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 compounds, 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. ...