The Glossary of Foundry and Casting
(O-P-Q-R-S-T)

To help metal casting buyers and sellers to understand more about metal casting and foundry operation terms. All terms have been arranged in alphabetical order.

A-B  C-D-E  F-G-H-I  J-K-L-M-N  O-P-Q-R-S-T  U-V-W-X-Y-Z

Oddsides
Semi-permanent molds of plaster of paris, graphite, or dry sand, tarred and dried and used for repetitive work in the foundry.

Off Iron
Pig iron that is not of the desired composition. See Pig Iron.

Off-Dimension
A casting defect caused by any incorrect dimension resulting from improper setting of cores, using wrong core, shifts, swells, etc. See Core.

Off-Gage (Off-Size)
Core defect caused by improper gagging of dimensions.

Off-Grade Metal
Metal whose composition does not correspond to the designated or applicable specification.

Oil And Whiting Test
A method of detecting fine cracks by applying a penetrating oil and painting the tested metal surface with a mixture of whiting and a thinner. Oil in the cracks emerges to stain the whiting.

Oil Core
A core bonded with oil.

Oil Mold
A mold in which the sand is bonded by an oil binder.

Oil Furnace
Furnaces fired with oil.

Oil Quenching
Quenching in oil. See Quenching.

Oil Sand Core
Core in which sand mass is bound by an oil-based binder.

Oil Sands
Sand bonded with such oils as linseed and the synthetics.

Oil Shot
In die casting, a sponge like whirl on the surface of casting resulting from an excess of oil applied to the sprue hole before the shot was made.

Oil-Oxygen Binder (Cold-Setting, Air-Setting Binders)
A synthetic auto-oxidizing liquid, oil-based binder that partially hardens at room temperature, using an oxygen releasing agent. Baking is needed to complete the hardening.

Olive
(Mg2Fe2SiO4) A naturally occurring mineral composed of fosterite and fayalite, crushed and used as a molding sand. Usually the sand of choice in manganese steel casting due to its basicity. See Molding Sand.

Olivine
Magnesium-iron-orthosilicate composed of forsterite and fayalite. Does not contain free silica. Possible molding material.

One-Piece Pattern
A solid pattern, not necessarily made from one piece of material. The pattern may have one or more loose pieces.

One-Screen
A distribution of a clean sand or a sand with two maximum screens separated by a minimum screen. These high-expansion problem sands are also referred to as camel back distributions.

Open Face Mold
See Open Sand Casting.

Open Flame Furnace
As opposed to the crucible furnace; in the open-flame furnace the metal charge is confined in the refractory lining, with the flame and products of combustion coming in direct contact with the metal.

Open Grain Structure
A defect wherein a casting, when machined or fractured, appears to be coarse grained and porous; usually due to a shrink area.

Open Riser
Riser whose top is open to the atmosphere through the top of the mold. See Riser.

Open Sand Casting
A casting poured into a mold which has no cope or other covering.

Open-Hearth Furnace
A furnace for melting metal, in which the bath is heated by the combustion of hot gases over the surface of the metal and by radiation from the roof. The furnace fuel may be producer gas, coke-oven gas, powdered coal, or oil.

Open-Hearth Steel
Steel made in open-heart furnace.

Optical Pyrometer
A temperature measuring device through which the observer sights the heated object and compares its incandescence with that of an electrically heated filament whose brightness can be regulated; or the intensity of the light admitted from the object may be varied through filters and compared with a constant light source. See Pyrometer.

Optimum Moisture
That moisture content which results in developing the maximum of any property of a sand mixture.

Orange Peel
A pebble-grained surface that develops in the mechanical forming of sheet metals with coarse grains.

Orange Peel Bucket
A bottom-drop bucket used for charging cupolas; the drop-bottom is divided into a number of sections that appear to peel back as the bucket opens.

Ore
A mineral from which a metallic element may be extracted profitably.

Oriffice
An opening of controlled size used to measure or control the flow of gases.

Oriffice Plate
In a cupola a device used to measure the volume of air delivered to the windbox.

Oscillating Trough Cooler
A steel trough conveyor within a plenum where reclaimed sand is cooled prior to reuse.

Osmondite
An obsolete term once used to designate a ferrous microstructure not so well defined as Troosite.

Ottawa Sand
A sand originating near Ottawa, IL. Also know as St. Peter sandstone.

Oven, Drying
A furnace or oven for drying molds or cores.

Ovens
See Continuous Annealing Furnace.

Overaging
Aging a precipitation-hardening alloy under conditions of time and temperature greater than those required to obtain maximum strength or hardness. See Aging.

Overfiring
Heating refractories to a temperature sufficient to cause pronounced vitrification, deformation, or bloating.

Overflows (Overflow wells)
Separated cavities cut into the face of die casting dies adjacent to the main cavity and connected to it by a channel, ensuring filling of cavity.

Overhand
Extension of the end surface of the cope half of a core print beyond that of the drag to provide clearance for closing of the mold. See Cope, Mold.

Overhang
The extension on the vertical surface of a core print, providing clearance for closing the mold over the core, also known as "shingle."

Overheated
A term applied when, after exposure to an excessively high temperature, a metal develops an undesirable coarse grain structure, but is not necessarily damaged permanently. Unlike burned structure, the structure produced by overheating can be corrected by suitable heat treatment, by mechanical work, or by a combination of the two.

Overstressing
Permanently deforming a metal by subjecting it to stresses that exceed the elastic limit.

Owen Jet Dust Counter
An instrument similar to the Konimeter, using the humidification factor.

Oxidation
Any reaction whereby an element reacts with oxygen.

Oxidation losses
Reduction in amount of metal or alloy through oxidation. Such losses usually are the largest factor in melting loss.

Oxide
A compound of oxygen with another element.

Oxidizing Atmosphere
An atmosphere resulting from the combustion of fuels in an atmosphere where excess oxygen is present, and with no unburned fuel lost in the products of combustion.

Oxidizing Flame
A flame produced with excess oxygen.

Oxygen Bomb Calorimeter
An instrument to measure the heats of combustion of solid and liquid fuels.

Oxygen Impingement Process
Pure oxygen is blown down on the bath to refine Pig Iron.

Oxygen Lance
See Lance, Oxygen.

Pack Hardening (Park Carburizing)
See Case Hardening.

Packing Or Packing Material
Sand, gravel, mill scale or similar materials used to support castings packed in annealing pots, to prevent possible warpage under high temperatures. See Annealing, Casting, Warpage.

Pad
Metal added deliberately to the cross section of a casting wall, usually extending from a riser, to ensure adequate feeding to a localized area in which a shrink might occur without the addition.

Padding
The process of adding extra material to a cross-section of a casting wall, usually extending from a riser to ensure adequate feed to a localized area where sharing would occur if the added material were not present. It must be machined off of casting.

Panel Spalling Test
A test using a panel of the refractory being tested to provide a reference to spalling behavior.

Panoramic Analyzer
An instrument for analyzing sounds and displaying the results either on an oscilloscope or a graph.

Papping Plate
A metal plate attached to a pattern to prevent injury to the pattern and assist in loosening it from the sand.

Parkerizing
A proprietary method of producing a protective phosphate coating on ferrous metals. Parker A treatment involves immersing in a bath of acid manganese phosphate. The Parker D is a modification using acid zinc phosphate with a nitrate iron as accelerator.

Parlanti Casting Process
A proprietary permanent mold process using dies of aluminum with a controlled rate of heat transfer.

Parsons Duncan Process
A method of casting steel ingots wherein the top layer of the mold is heated and the last to solidify.

Parted Pattern
A pattern made in two or more parts.

Partially Graphitized Cast Iron
A blackheart malleable casting only partly graphitized in annealing, giving a mixture of black and white. Sometimes termed salt and pepper fracture. See Cast Iron.

Particulate Matter
In air pollution control, solid or liquid particles, except water, visible with or without a microscope, that make up the obvious portion smoke.

Parting
The joint, dividing line, where mold separates to permit removal of the pattern.

Parting Agent
See Release Agent.

Parting Compound
Material dusted or sprayed on a pattern or mold to prevent adherence of sand.

Parting Line
A line on a pattern or casting corresponding to the separation between the cope and drag portions of a sand mold. The joint where mold separates to permit removal of pattern. See Casting, Cope, Drag, Mold, Pattern.

Parting Sand
A bondless sand dusted on the parting to prevent the parts of the mold from adhering to each other.

Passivator
An inhibitor which changes the potential of a metal to a more cathodic value.

Passivity
The property of some metals to become abnormally inactive towards certain reagents.

Patching
Repair of a furnace lining or repair of a mold core.

Pattern
An original used as a form to produce duplicate pieces. Pattern dimensions are slightly enlarged to counteract the shrinkage of the casting as it solidifies and cools in the mold. Although patterns can be made in one piece, a complicated casting may consist of two or more parts. The pattern may be made out of wood, plastic, metal, or other material. See Casting, Mold, Solidification.

Pattern Coating
Coating material applied to wood patterns to protect them against moisture and abrasion of molding sand.

Pattern Draft
The taper allowed on the vertical faces of a pattern to permit easy withdrawal of pattern from the mold or die.

Pattern Layout
Full-sized drawing of a pattern showing its arrangement and structural features.

Pattern Letters
Metal or plastic letters or figures in various sizes which are affixed to patterns for identification purposes.

Pattern Shrinkage
The shrinkage allowance made on all patterns to compensate for the change in dimensions as the solidified casting cools in the mold from freezing temperature to room temperature. Pattern is made larger by the amount of shrinkage characteristic of the particular metal in the casting and the amount of resulting contraction to be encountered. Rules or scales are available for use. See Casting, Shrinkage, Pattern.

Pattern, Split
Pattern usually made in two parts, sometimes in more than two.

Patternmaker(s)
A craftsman engaged in production of foundry patterns from wood, plastic, or metals, such as aluminum, brass, etc. See Pattern.

Patternmaker's Shrinkage
The shrinkage allowance made on all patterns to compensate for the change in dimensions as the solidified casting cools in the mold from freezing temperature of the metal to room temperature. Pattern is made larger by the amount of shrinkage characteristic of the particular metal in the casting and the amount of resulting contraction to be encountered. Rules or scales are available for use.

PCE
Abbreviation for Pyrometric Cone Equivalent.

Pearlite
A microconstituent of iron and steel consisting of alternative layers of ferrite and iron carbide or cementite.

Pearlitic Malleable Iron
A malleable iron in which the iron matrix is made higher strength/lower ductility through heat treatment. See Pearlite.

Peel
Free removal of burnt molding sand from casting.

Peen
Peening action obtained by impact of metal shot, often used to improve fatigue properties by putting the surface in compression. Also the small end of a molder's hammer.

Pencil Core
A core projecting to the center of a blind riser allowing atmospheric pressure to force out feed metal. See Blind Riser.

Penetrameter
A strip of metal with stepped thickness variation and with holes at varying depths; used in radiography to indicate the sensitivity of the radiograph.

Penetration, Metal
Condition where molten metal has penetrated into the sand, resulting in a mixture of metal and sand adhering to the casting.

Periclase
Natural magnesia in nodular form, formed by heating.

Perlite
A highly siliceous volcanic rock which can be expended by heating into a porous mass of particles. Perlite can be used as an insulation in foundry sand mixtures. Not to be confused with Pearlite.

Permanent Mold
A long-life mold into which metal is poured by gravity. It is used repeatedly to produce many castings from the same mold. It is not an ingot mold. See Mold.

Permeability
The property of a mold material to allow passage of gases. The property in sand molds which permits the passage of gases.

pH
A symbol denoting the negative logarithm of the concentration of the hydrogen ion in gram-atoms per liter, used in expressing both acidity and alkalinity; pH=log 1/H per liter. An important factor in foundry sand control, pH7 is neutral; values less than 7 acid, and higher than 7, basic. At 25°C, the neutral value is 7. Acidity increases with decreasing values below 7, and basicity increases with increasing values above 7.

Phase
A constituent which is completely homogeneous, and is both physically and chemically separated from the rest of the alloy by definite bounding surfaces; for example, austenite, ferrite, cementite. Not all constituents are phases; pearlite for example. See Austenite, Cementite, Pearlite.

Phase Diagram
(1) A graphic representation of the equilibrium temperature and composition limits of phase fields reactions in an alloy system. In a binary system, temperature is usually the ordinate and composition the abscissa. Ternary and more complex systems require several two-dimensional diagrams to show the temperature-composition variables completely. In alloy systems, pressure is usually considered constant, although it may be treated as an additional variable. (2) Graphical representation of the equilibrium temperatures and the composition limits of phase fields and phase reactions in an alloy system.

Phenolic Resin (One-step)
A resin made by the polymerization of a phenol with an aldehyde; used a binder for cores and sand molds. See Urea-Formaldehyde Resin.

Phosphorus
One of the elements; its chemical symbol is P. Its formula weight is 123.92; specific gravity 1.82, and melting point 44.1°C.

Photomicrograph
A photograph of the grain structure of a metal as observed when optically magnified more than 10 diameters. The term micrograph may be used.

Physical Metallurgy
The science concerned with the physical and mechanical characteristics of metals and alloys.

Physical Properties
Properties of matter such as density, electrical and thermal conductivity, expansion, and specific heat. This term should not be used interchangeably with "mechanical properties."

Picral
An etchant for ferrous alloys; 4% picric acid in alcohol.

Pig Iron
Blocks of iron to a known metal chemical analysis used for melting, with suitable additions of scrap, etc., for the production of ferrous castings. See Ingot.

Pig Iron, Basic
A grade of iron made from the basic open-hearth process of steelmaking; P, 0.40% maximum for Northern iron, 0.70 to 0.90% for Southern iron; S 0.05% maximum and Si, 1.50%.

Pig Iron, Chateaugay
Pig iron from Chateaugay (New York State). Ores that very low in phosphorus, copper-free, and containing appreciable amounts of titanium.

Pilot Casting Or Sample Casting
A casting made from a pattern produced in a production die to check the accuracy of dimensions and quality of castings which will be made in quantity. See Casting.

Pinhole
Small hole under the surface of a casting. See Casting.

Pins, Fask
Hardened steel locating pins used on flasks to ensure proper register of cope and drag molds. See Cope, Drag.

Pipe
A cavity formed by shrinkage of the metal during solidification of the last portion of liquid metal, usually occurring in a riser having feeder metal for the casting. See Cavity, Casting.

Pit Mold
Mold in which the lower portions are made in a suitable pit or excavation in a foundry floor. See Foundry.

Pitch
Usually coal-tar pitch obtained in manufacture of coke and distilled off at about 350°F. Used as a binder in large cores and molds. Melting range is 285°F to 315°F.

Pitting
A form of wear characterized by the presence of surface cavities, the formation of which is attributed to processes such as fatigue, local adhesion, cavitation or corrosion.

Plane Strain
A stress condition in linear elastic fracture mechanics (see LEFM) in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth. Under plane strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress.

Plasma Refining
Process used to reduce sulfur and oxygen to very low levels.

Plaster Molding
Molding method wherein gypsum or plaster of Paris is mixed with fibrous talc, with or without sand, and with water to form a slurry that is poured around a pattern. In a short period of time, the mass air-sets or hardens sufficiently to permit removal of the pattern. The mold so formed is baked at elevated temperature to remove all moisture prior to use. One variation is the Antioch process.

Plaster of Paris
A semi-hydrated form of calcium sulfate made by sintering gypsum to 120°C-130°C (248°F-266°F).

Plastic Deformation
Permanent distortion of a material under the action of applied pressure.

Plastic Pattern
Pattern made from any of the several thermosetting-type synthetic resins such as phenol formaldehyde, epoxy, etc. Small patterns may be cast solid, but large ones are usually produced by laminating with glass cloth.

Plates, Bottom
Plates, usually of metal, on which molds are set for pouring.

Plates, Core Drying
Flat plates of metal on which cores are placed for baking.

Plumbago
Powdered graphite. See Printing Back.

PMMA
Abbreviation for Polymethymethacralate. Foam used in the lost foam process, does release as much carbon as polystyrene.

Pneumatic Tools
Grinders, rammers, drills, etc., operated by compressed air.

Pocket
A body of sand surrounded on all but one side by molten metal.

Pohland Method
A technique for the ultrasonic testing of steel in which a visible image of the defects present in the steel can be shown on a screen.

Polystyrene
A polymer of styrene used in making molding products. In particular, used in the lost foam process.

Porosity
Unsoundness in castings appearing as blowholes and shrinkage cavities.

Porosity (Blow-Holes)
Holes in the casting due to gases trapped in the mold, reaction of molten metal with moisture in the molding sand, or imperfect fusion of chaplets with molten metal. (Surface porosity may be due to overheating of the mold or core faces, but should not be confused with sand inclusions.) See Blow Hole, Blow Holes, Inclusion, Molding Sand.

Postheating
A process used immediately after welding whereby heat is applied to the weld zone either for tempering or for providing a controlled rate of cooling, in order to avoid a hard or brittle structure.

Pot
Term usually applied to cast iron containers used in melting aluminum-base alloys; also used to describe steel crucibles for melting magnesium-base alloys, as well as graphite crucibles. See Alloy, Crucible.

Pour
Discharge of molten metal from the ladle into the mold.

Poured Short
Casting which lacks completeness due to the cavity not being filled with molten metal.

Pouring
Filling the mold with molten metal. Transfering the molten metal from the furnace to the ladle, ladle to ladle, or ladle into the molds. See Molds, Ladle.

Pouring Basin
Reservoir on top of the mold to receive the molten metal.

Pouring Basin, Cup
Located on top of sprue or downgate. That portion of the gating.

Pouring Cup
The flared section of the top of the downsprue. It can be shaped by hand in the cope, or be a shaped part of the pattern used to form the downsprue; or may be baked core cup placed on the top of the cope over the downsprue. See Baked Core.

Pouring Device
Mechanically operated device with a ladle set for controlling the pouring operation.

Pouring Ladle
Ladle used to pour metal into the mold. See Casting, Ladle, Mold.

Pouring Off
The task of ladling, or mechanically pouring, of the molten metal into the molds, forming the casting. See Casting.

Powder Cutting
Introducing iron powder in an oxygen stream to hasten oxygen torch cutting by the combination of fluxing and oxidation. Generally used for cutting stainless steel.

Powdered Coal
Finely ground, high-volatile coal used for heating furnaces and annealing ovens in the malleable foundry industry.

Precipitation Hardening
A process of hardening an alloy in which a constituent precipitates from a supersaturated solid solution.

Precipition Heat Treatment
Any of the various aging treatments conducted at elevated temperatures to improve certain mechanical properties through precipitation from solid solution. See Heat Treatment.

Preheating
A general term for heating material, as a die in die casting, as a preliminary to operation, to reduce thermal shock and prevent adherence of molten metal.

Pressure Die Casting
A British term. See Die Casting.

Pressure-Tight
A term describing a casting free from porosity of the type that would permit leaking.

Primary Choke (Choke)
That part of the gating system which most restricts or regulates the flow of metal into the mold cavity. See Gate.

Primary Crystals
The first dendritic crystal that form in an alloy during cooling below the liquid's temperature.

Print
Part of the core used to locate and support-part of a pattern to form area in mold for same purpose; part of mold and part in core box for the same purpose. See Core, Mold, Core Box.

Print Back
After the surface of a mold is dusted with graphite facing, the pattern is replaced, rapped into position and again removed.

Printing Back
To dust the cavity with Plumbago and reprint pattern. It smoothes the cavity surface by filling voids. See Plumbago.

Process Capability
The amount of variation in the output of a controlled manufacturing process, the range defined by plus or minus three standard deviations.

Product Analysis
In castings, the analysis of the actual part as opposed to the analysis of the steel from which the casting was poured.

Production Foundry
Highly mechanized foundry for manufacturing large quantities of repetitive castings. See Foundry.

Production Welding
Any welding carried out during manufacturing before final delivery to the purchaser. This includes joint welding of casting and finishing welding.

Proeutectoid
The constituent that separates out of a solid solution before the formation of eutectoid. See Eutectoid.

Profile Tolerances
A system of locating and tolerancing developed to control the orientation of rough parts in machine fixtures. From locating points on the casting a "perfect profile" is established for all surfaces and features. A tolerance envelope surrounding that profile defines the limitations of an acceptable part.

Progressive Solidification
See Directional Solidification.

Protection Tube
A metal, graphite, or ceramic tube which shrouds and protects the wires of a thermoelectric pyrometer. See Pyrometer.

Psi
Abbreviation for pounds per square inch.

Pugnill
A mill for mixing foundry sands and sand mixtures consisting essential of a shaft fitted with plows or paddle wheel which revolve in a tub or vat. See Foundry Sand.

Punchout Machines
A machine used to force the entire sand and casting contents from the molding box in one motion, without the use of vibration.

Purging
Elimination of air and other undesirable gases from furnaces or heating boxes.

Purifiers, Flux
Various materials added to molten metals and alloys for the purpose of removing impurities, gases, etc.

Push-Up
An indentation in the casting surface due to displacement (expansion) of the sand in the mold.

Pyrometallurgy
Chemical metallurgical process dependent upon heat.

Pyrometer
An instrument for determining elevated temperatures.

Pyrometric Cone
A slender trihedral pyramid made of a mixture of minerals similar in composition to that of a clay or other refractory being tested. Each cone is assigned a number indicating its fusion temperature.

Pyrometric Cone Equivalent (PCE)
An index of refractoriness obtained by heating on a time-temperature schedule a cone of the sample material and a series of standardized pyrometric cones of increasing refractoriness.

Pyrometry
A method of measuring temperature with any type of temperature indicating instruments. See Pyrometer.

Quartz
A form of silica occurring in hexagonal crystals which are commonly colorless and transparent, but sometimes also yellow, brown, purple, green, etc. It is the most common of all solid minerals. See Silica.

Quartzite
A compact granular rock composed of quartz. It is a metamorphosed sandstone, and siliceous cement is often so blended with the quartz grains as to give the rock a nearly homogeneous texture. Primary materiel in silica brick.

Quench Crack
A crack resulting from thermal stress induced during rapid cooling or quenching, or from stresses induced by delayed transformations some time after the article has been fully quenched.

Quench Severity
The quench severity is characterized by the H value and relates to the rate of temperature change during quenching.

Quenching
Rapid cooling of hardening; normally achieved by immersion of the object to be hardened in water, oil, or solutions of salt or organic compounds in water.

Radiant Heat
Heat communicated by radiation and transmitted by electromagnetic waves.

Radiation Area
Any part of an installation accessible to employees in which there exists a radiation level of 7.5 millirem in any one hour over 150 millirem in any seven consecutive days.

Radiation Hazard
Any situation where persons might be exposed to radiation in excess of the maximum permissible dose.

Radiation, Direct
All radiation coming from within an x-ray tube and tube housing except the useful beam.

Radioactive Isotope
Varieties of an element possessing the same chemical characteristics but emitting detectable radiation's by means of which they can be identified and traced.

Radioactive Material
Any compound or element which may emit any or all of the following: alpha and beta particles, electrons, photons neutrons and gamma and all other emissions which produce ionization directly or indirectly.

Radiographic Inspection
Examination of the soundness of a casting by study of radiographs taken in various areas or of the whole casting.

Radiographic Testing
Use of x-or gamma rays in studying the internal structure of objects to determine their homogeneity.

Radium
A radioactive element which the chemical symbol Ra; radium and its salts are used in gamma-ray radiography because of their radioactivity. Radium's melting point is 700°C (1,292°F).

Ram
Process of packing sand in a mold using a hand, pneumatic or mechanized ramming device.

Rammer
Tool for ramming the sand. See Ramming.

Ramming
Packing sand in a mold by raising and dropping the sand, pattern, flask on a table. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle.

Ramming Up
The process of packing the sand in the mold or core box with a rod or rammer.

Ram-Up Core
See Core, Ram-Up.

Range
The difference between the highest and lowest values of a measurable attribute of the output of a process.

Rapping
Loosening the pattern from the mold by jarring or knocking.

Rapping Bar
A pointed bar or rod made of steel or other metal, which is inserted vertically into a hole in a pattern, or driven into it, then struck with a hammer on alternate sides to cause vibration and loosening of the pattern from the sand.

Rapping Plate
Metal plate attached to a pattern to permit rapping for removal from the sand.

Rare Earth (RE)
Any of a group of 15 similar metals with atomic numbers 57 to 71. Also rare earth element, rare earth metal, lanthanide series, uncommon metals, Mischmetal.

Rare Gases
These include helium, argon, neon, krypton, xenon and radon.

Rat Tail
An expansion discontinuity in a sand casting, featured as a long, narrow, linear depression, resulting from sand expansion and minor buckling of the mold surface during filling of the mold.

Rebonding
Term usually employed in reference to adding new bonding material to used molding sand so that it can be used again to produce molds.

Receiving Ladle
A ladle placed in front of the cupola into which all metal is tapped. It acts as a mixer and reservoir and to smooth out metal flow to the pouring area. See Cupola, Ladle.

Rechucking
Reversing a pattern upon a face plate to permit turning the opposite face to the required shape.

Recovery Rate
Ratio of the number of parts scrapped to the total number of parts manufactured, expressed as a percentage.

Recrystallization
A process whereby the distorted grain structure of cold-worked metals is replaced by a new, strain-free grain structure during annealing above a specific minimum temperature.

Recrystallization Temperature
The lowest temperature at which the distorted grain structure of a cold-worked metal is replaced by a new, strain-free grain structure during prolonged annealing. Time, purity of the metal, and prior deformation are important factors.

Reducing Flame
Flame burning with insufficient oxygen to provide complete combustion, resulting in the presence of carbon in the flame.

Reduction
The removal of oxygen or addition of hydrogen.

Reflectoscope
An instrument for the ultrasonic testing of metals.

Refractory
Heat-resistant material, usually non-metallic, used for furnace linings etc. The quality of resisting heat. Material usually made of ceramics, which is resistant to high temperatures, molten metal, and slag attack.

Refractory Clay
A clay which fuses at pce 25 (1590°C, 2894°F) or higher.

Regression Analysis
A statistical method of determining, or predicting, the value of a dependent variable, based on levels of one or more know independent variables.

Reject Rate
Ratio of the number of parts scrapped to the total number of parts manufactured, expressed as a percentage.

Release Agent (Parting Agent)
A material, e.g. silicone, stearate, oil, or wax for lubricating a die pattern or core box to facilitate easy removal of a casting, mold or core.

Relief Sprue
The term usually refers to a second sprue at opposite end of the runner to relieve pressure created during pouring operation.

Remanence
The remaining flux density after the magnetizing force has been removed.

Remelt
See Revert.

Repair Welding
Any welding carried out after delivery to the end user, i.e., after the casting has been in service.

Replicast Process (CS)
A ceramic shell process similar to the investment casting process. Uses a pattern made from expanded polystyrene (EPS) and is surrounded by a thin ceramic shell.

Residual
Any element remaining in any alloy following melting and casting which was not added to meet an analytical specification limit.

Residual Stress
See Stress, Residual.

Resin Binder
Any of the thermosetting types of resins used as binders for producing cores and shell molds, such as phenol and urea formaldehydes, melamines, furans (fufuryls and furfuryl alcohol), etc.

Resin-Coated Sand
Molding or core sand in which the binder is resin applied to the sand as a coating by either cold or hot coating. See Binder, Core Sand, Molding Sand.

Resolved Shear Stress
Stress operating on a crystallographic slip system.

Respirator
A filtering device which covers the nose and mouth and prevents inhalation of dust or fumes; should have the U.S. Bureau of Mines certificate or approval for the specific contaminant being filtered out. Handkerchiefs and gauze masks give little or no protection.

Returns
Metal in the form of gates, sprues, risers or defective castings which are put back into the melting cycle. See Casting, Gate, Riser, Sprue.

Reverberatory Furnace
Melting unit with a roof arranged to deflect the flame and heat toward the hearth on which the metal to be melted rests.

Revert
Recycled sprues, gates, risers, defective castings and machine chips.See Casting, Gate, Riser, Sprue.

Reynolds Numbers
Used in hydraulics and in casting gating theory. A dimensionless value (dynamic viscosity / density) describing the fairly sudden shift of flow from laminar to turbulent. Re > 2000 represents turbulent flow. Laminar flow is seldom experienced in runner and gating systems.

Rheocasting
Also called flow casting. A metal forming process in which a semi-solid metal is used to make the casting. The solid metal is heated to a partly liquid, softened state and then pressed into the final form. The finished part has closer tolerances, better surface finish, higher strength, and lighter weight than a similar part made with traditional casting techniques.

Riddle
Hand- or power-operated device for removing large particles of sand or foreign material from foundry sand.

Rigging
Gates, risers, loose pieces, etc., needed on the pattern to produce a sound casting. See Casting, Gate, Riser, Loose Pieces, Pattern.

Rimmed Steel
A low-carbon steel.

Ringelmann's Scale
In air pollution control, a black and white mesh scale reading from all clear to solid black, used to measure the density of smoke. Observer normally uses chart comparator 50 feet from the point where smoke emits.

Riser
A reservoir of molten metal that the casting can draw from to offset the shrinkage that is taking place as the metal solidifies. See Feeder.

Riser Contact
The connecting passage between a riser and a casting. See Casting, Riser.

Riser Distance
The length of the riser neck. The term is applied to side risers only. See Riser Neck.

Riser Gating
Gating system in which molten metal from the sprue enters a riser close to the mold cavity and then flows into the mold cavity. See Mold Cavity.

Riser Height
The distance from the top of the riser when liquid to the top of the riser neck. Riser height when sold is usually several inches less than when liquid because of contraction and loss of feed metal to the casting.

Riser Neck
The connecting passage between the riser and casting. Usually only the height and width or diameter of the riser neck are reported, although the shape can be equally important.

Riser Pad (Riser Contact)
An enlargement of the riser neck where it joins the casting. The purpose of the pad is to prevent the riser from breaking into the casting when it is struck or cut from the casting.

Riser, Blind
A riser that does not break through the top of the cope and is entirely surrounded by sand; opened to the atmosphere by means of a firecracker core.

Riser, Open
Conventional form of riser usually located at the heaviest section of the casting and extending through the entire height of the cope.

Riser, Side (Side Head)
A riser attached to the side of a casting.

Riser, Top (Top head)
A riser attached to the top surface of a casting.

Riser-Gating
Practice of running metal for the casting through the riser to help directional solidification.

Rockwell Hardness
See Hardness.

Rockwell Hardness Testing
Method of determining the indentation hardness by measuring the depth of residual penetration by a steel ball or a diamond cone. See Hardness.

Rodding
Reinforcing the sand in a core with metal rods or shapes to strengthen parts of the core.

Rolling Over
Operation of turning flask over to reverse its position. Positioning the mold so that the pattern faces upward in order to be removed. See Core, Cope, Flask.

Rollover Board
A wood or metal plate on which the pattern is laid top face downward for ramming the drag half mold, the plate and half mold being turned over together before the joint is made. See Pattern.

Rollover Machine
A molding machine with which the flask is rolled over before the pattern is drawn from the mold.

Runner
Trapezoidal shaped piece that runs horizontally to the mold cavity and connects the Sprue base to the gate(s). See Gate, Sprue.

Runner Box
System into which molten metal is introduced.

Runner Extension
In a mold, part of a runner which extends beyond the farthest ingate as a blind end. It acts as a dirt trap and is sometimes vented. See Dirt Trap.

Runner Riser
A conventional runner, usually in the horizontal plane, which permits flow of molten metal to the in gate and is large enough to act as a reservoir to feed the casting.

Runner System (Gating)
The set of channels in a mould through which molten metal is poured to fill the mold cavity. The system normally consists of a vertical section (downgate or sprue) to the point where it joins the mold cavity (gate) and leading from the mould cavity further vertical channels (risers or feeders). See Riser, Feeder, Mold Cavity.

Runout
Metal flowing through a defect in the mold.

SAE Specifications
A set of materials specification issued by the Society of Automotive Engineers, Inc.

Sag
A decrease in metal section in casting due to sagging of the cope or core. See Core, Cope.

Salamander
A heating device, usually of drum shape, in which fuel is burned in the open air by natural draft. Iron material which has collected in the bottom of a blast furnace during a blow. See Blast Furnace, Blow.

Salt Bath
A bath of molten salts used for heating steels, for hardening or tempering.

Sand
In metalcasting, a loose, granular material high in SiO2, resulting from the disintegration of rock. The name sand refers to the size of grain and not to mineral composition. Diameter of the individual grains can vary from approximately 6 to 270 mesh. Most foundry sands are made up principally of the mineral quartz (silica). Reason for this is that sand is plentiful, refractory, and cheap; miscellaneous sands include zircon, olivine, chromite, CaCO3, black sand (lava grains), titanium minerals and others.

Sand Blast
Sand driven by a blast of compressed air (or steam). It is used to clean castings, to cut, polish, or decorate glass or other hard substances, and also to clean building fronts, etc.

Sand Casting
Metal castings produced in sand molds. See Casting.

Sand Conditioning
Preparation of used molding sand for reuse, which includes additions of bond, additives, moisture, etc.

Sand Control
Procedure whereby various properties of foundry sand, such as fineness, permeability, green strength, moisture content, etc., are adjusted to obtain castings free from blows, scabs, veins, and similar defects. See Foundry Sand.

Sand Control Equipment
Testing instruments such as moisture determinators, permeability air-flow apparatus, etc., for determining the various physical properties of sands.

Sand Dryer
Apparatus for removing moisture from sand.

Sand Holes
Cavities of irregular shape and size whose inner surfaces plainly show the imprint of granular material.

Sand Inclusions
Cavities or surface imperfections on a casting caused by sand washing into the mold cavity. See Mold Cavity.

Sand Molding
Process in which moist sand is compressed into a hollow form. Molten metal is then poured into the form to fill the cavity. When the metal has solidified, the sand is broken away by vibration leaving the metal casting.

Sand Muller
A machine for mixing sand by kneading and squeezing. See Muller.

Sand Mulling
A method of evenly distributing the bond around the sand grain by a rubbing action.

Sand Plow
A bladed device used to divert sand from a belt conveyor into a sand hopper.

Sand Porosity
Volume of the pore spaces or folds in a sand. (Not synonymous with permeability).

Sand Reclaimer
Equipment for removing extraneous material from used sand and reconditioning it for further use.

Sand Reclamation
Processing of used foundry sand grains by thermal, attraction or hydraulic methods so that it may be used in place of new sand without substantially changing current foundry sand practice. See Foundry Sand.

Sand Slinger
Molding machine which throws sand into a flask or corebox, by centrifugal action. See Flask, Core Box.

Sand Tempering
Dampening and cutting over or otherwise mixing sand to produce uniform distribution of moisture, and allowing time for migration of water molecules.

Sand Toughness
Indication of molding sand workability, particularly with reference to ramability, because the tougher the sand, the harder it is to ram tightly against the pattern. It is usually given as a number obtained by multiplying deformation by green compressive strength times 1000. See Molding Sand.

Sand Wall
Temporary independent wall separated from a slag pocket wall; facilitates slag removal and protects permanent wall.

Sand, Backing
Sand in a mold back of the facing.

Sand, Bank
Sand from a bank or pit.

Sand, Blast
Sand used in an abrasive blasting machine for cleaning castings.

Sand, Core
Sand used in making cores.

Sand, Facing
Prepared sand used next to the pattern.

Sand, Floor
Sand used in floor molding.

Sand, Heap
Sand prepared on foundry floor.

Sand, Lake
Sharp sand from vicinity of lakes.

Sand, Molding
Sand used to make molds.

Sand, Natural
Naturally bonded sand as distinguished from that which is formed synthetically. See Naturally Bonded.

Sand, Open
Sand through which gases can pass freely.

Sand, Silica
Sand composed of almost pure silica.

Sand, Synthetic
Molding sand prepared by adding clay or other bond to the sand which is practically free of those materials. See Natural Sand.

Scab
A blemish on a casting caused by eruption of gas from the mold face.

Scaling (Scale)
Surface oxidation, partially adherent layers of corrosion products, left on metals by heating or casting in air or in other oxidizing atmospheres.

Scanning Electron Microscope (SEM)
An instrument used for obtaining microstructure images using an electron beam. The micrographs obtained give depth perception of the metal being observed.

Scarfing
Cutting off surface projections such as gates and risers from casting by means of gas torch.

Scrap
Any scrap metal melted, usually with suitable additions, to produce castings.

Scrap Metal
Metal to be remelted; includes scrapped machinery fabricated items such as rail or structural steel and rejected castings (metal to be re-melted, castings that have to be re-melted).

Screen Sand
A sieve or riddle with openings of definite size used to separate one gain size from another or to remove lumps from sand.

Screen Analysis (Sieve Analysis)
Distribution of particle size sand expressed in terms of the percentage of weight retained on each of a series of standard screens decreasing in mesh size and the percentage passed by the screen of finest mesh.

Scrubbers
See Wet Scrubbers.

Sea Coal
Term applied to finely ground bituminous coal which is mixed with sands for foundry uses.

Sealed Source
Any radioactive material that is encased in and is to be used in a container in a manner intended to prevent leakage of the radioactive material.

Seam
A surface defect on a casting related to but of lesser degree than a Cold Shut; a ridge on the surface of a casting caused by a crack in the mold face. See Cold Shut.

Segregation
A concentration of alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid.

Selenium
A metalloid melting 220°C (428°F) added to stainless steel to improve machinability.

Separator
A mechanical unit which separates or grades ground materials into constituent parts, used in the foundry to remove fines from the system sand and dust from the air.

SG Iron
Term used in Britain and continental Europe for ductile or nodular iron. SG means spherulitic or spheroidal graphite.

Shakeout
The process of separating the solidified casting from the mold material. The stage in the casting process where the sand from the mold is cleaned off of the newly formed castings through vigorous vibration. See Casting, Molds, Vibrator.

Shakeout Machinery
Equipment for mechanical removal of castings from molds.

Shank
The handle attached to a small ladle. See Ladle.

Sharp Sand
Sand free from binders, i.e., new, clean sand of angular shape. The term does not refer to grain shape. See Binder.

Shaw (Osborn-Shaw) Process
A precision casting technique in ceramic molds which do not require wax or plastic investment. See Lost Wax Process, Investment Casting.

Shear
A type of deformation in which parallel planes in the metal crystals slide so as to retain their parallel relation.

Shear Modulus (G)
In a torsion test, the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range. Units are Pa or psi.

Shear Strain
Elastic displacement produced by pure shear loading.

Shear Strength
Maximum shear stress a material is capable of withstanding without failure.

Shear Stress
Load per unit area parallel to the plane of contact.

Shell Molding
A process for forming a mold from resin-bonded sand mixtures brought in contact with pre-heated (300°F - 500°F) metal patterns, resulting in a firm shell with a cavity corresponding to the outline of the pattern. See Cavity, Pattern.

Shell Process
Process in which clay-free silica sand coated with a thermosetting resin or mixed with resin is placed on a heated metal pattern for a short period of time to form a partially hardened shell. The bulk of the sand mixture inside the resulting shell is removed for further use. The pattern and shell are then heated further to harden or polymerize the resin-sand mix, and the shell is removed from the pattern. Frequently, shell cores are made using the Hot Box process. See Hot Box Process.

Shewed Tolerances
Tolerances which are non-symmetrically distributed about the design parameter.

Shift
A casting defect resulting form a mismatch of cope and drag. Sometimes there is a Core Shift, which also produces defective casting. See Core Shift.

Shortness (Hot)
Brittleness in a metal at an elevated temperature.

Shot
Metallic abrasive commonly used for cleaning casting surfaces. In die-casting, it is the phase of the die-casting cycle when molten metal is forced into the die.

Shotblasting (Shot peening)
Casting cleaning process employing a metal abrasive (grit or shot) propelled by centrifugal or air force.

Shrink
The difference in volume between liquid metal and solid metal or the void (shrink hole) left in a casting because of it.

Shrink Hole
A cavity in a casting due to insufficient feed metal. See Cavity.

Shrink Rule
Patternmaker's rule graded to allow for metal contraction.

Shrinkage
Difference in volume between liquid metal and solid metal in a given cavity. Contraction of metal in the mould during solidification. The term is also used to describe the casting defect, i.e. shrinkage cavity. This results from poor design, insufficient metal feed, or inadequate feeding.

Shrinkage Cracks
Cracks that form in metal as result of the pulling apart of grains by contraction before complete solidification. See Solidification.

Shrinkage, Centerline
Shrinkage occurring in the center of casting sections, particularly with platelike or barlike contours, which solidify simultaneously from two faces and cut off feeding in the central portion.

Shrinkage, Patternmakers
A linear scale or ruler, typically in inches or millimeters which has been lengthened by the percentage of linear shrinkage by which liquid metal contracts during solidification and cooling. See Solidification.

Sieve
A device with meshes of wire or other material for separating fine material from coarse material.

Sieve Analysis
See Screen Analysis.

Silica
Silicon dioxide, SiO2, occurring in nature as quartz, opal, etc. Molding and core sands are impure silica. The prime ingredient of sand and acid refractories.

Silica Brick
Refractory material of ganister, bonded with hydrated lime, and fired at high temperature.

Silica Flour
Silica in finely divided form.

Silica Gel
A colloidal form of silica used as a drying agent.

Silica Sand
Sand with a minimum silica content of 95% used for forming casting molds.

Silica Wash
Silica flour mixed with water and other materials to form a brushable or sprayable facing material.

Silicon
An abundant element, chemically classed as a nonmetal, metallurgically a metal, used extensively in ferrous and nonferrous alloys; melting point 1423ƒC (2593.4ƒF).

Silicon Brass
A series of alloys containing 0.5-6% silicon, 1-19% zinc and a substantial amount of copper. See Alloy.

Silicon Bronze
A series of alloys containing 1-5% silicon, 0.5-3% iron, under 5% zinc, under 1.5% manganese, and the remainder being substantially copper.

Silicon Carbide Briquets
Silicon carbide in briquet form used as an inoculant and deoxidizer in cupola-melted gray iron.

Silicon-Aluminum
An alloy of 50% silicon and 50% aluminum used for making silicon additions to aluminum alloys; also called an intermediate or hardener alloy. Melting point is 1070ƒF. See Alloy.

Silicon-Copper
An alloy of silicon and copper, used as a deoxidizer and hardener in copper-base alloys, which is available in tow types containing 10 and 20% silicon.

Silvery Iron
A type of pig iron containing 8-14% silicon, 1.50% carbon max., 0.06% sulfur max., and 0.15% phosphorus max. See Pig Iron.

Simultaneous Engineering
Refers to the process where user/designer and producer interact to reduce lead time and improve the efficiency of a part. This process is faster and more efficient than the traditional sequential process of design and manufacture.

Sintering
The bonding of adjacent surfaces of particles of a mass of powder or a compact by heating to a suitable temperature and cooling.

Sintering Point
That temperature at which the molding material begins to adhere to the casting, or in a test when the sand coheres to a platinum ribbon under controlled conditions. Also, the temperature at which sand grains begin to adhere to one another.

Sizing
A primary coating of glue applied to the end grain of wood to seal the pores.

Skeleton Pattern
A framework representing both the exterior and interior of the shape of the casting.

Skim Bob
Small upward bulge in the grating system, near the casting cavity, which functions as a dirt trap.

Skim Core (Skimmer)
A flat core or tile placed in a mold to skim a flowing stream of metal. Commonly used in pouring basins, it hold back slag and dirt while clean metal passes underneath to the downsprue.

Skim Gate
A gating arrangement which changes the direction of flow of molten metal and prevents the passage of slag and other undesirable materials into the mold cavity. See Mold Cavity, Slag.

Skimmer
A device or tool for removing slag and dross from the surface of molten metal. See Dross, Slag.

Skimming
Removing or hold back dirt or slag from the surface of the molten metal before or during pouring.

Skin
A thin surface layer different chemically or structurally from the main mass of a metal object. The surface of a mold or casting. See Casting, Mold.

Skin-Drying
Drying the surface of the mold by direct application of heat.

Slab Core
A plain flat core.

Slag
A fused nonmetallic material used to protect molten metal from the air and to extract certain impurities. The nonmetallic covering on molten metal resulting from the combination of impurities in the initial charge like ash from fuel, and any silica and clay eroded from the refactory lining. It is skimmed off prior to pouring the metal.

Slag Inclusions
Casting surface imperfections similar to sand inclusions, but containing impurities from the charge materials, silica and clay eroded from the refractory lining, ash from the fuel during the melting process. May also originate from metal-refractory reactions occurring in the ladle during pouring of the casting. See Inclusions.

Slag Trap
An enlargement, dam or protrusion in the gating or runner system in a mold for the purpose of preventing molten slag particles from entering the mold cavity. See Dirt Trap.

Slicking (Sleeking)
Smoothing the surface of molds.

Slip Casting
In ceramics, a pouring slip, a water suspension of finely ground clay, into a plaster of Paris mold. After it hardens it is dried and fired.

Slurry
A flow able mixture of refractory particles suspended in a liquid. Thin watery mixture such as the gypsum mixture for plaster molding, the molding medium used for investment casting, core dips, and mold washes. See Dip Coat.

Slush Casting
Casting made by pouring an alloy into a metal mold, allowing it to remain sufficiently long to form a think solid shell, and then pouring out the remaining liquid metal. See Alloy, Casting.

Smelter
An individual or firm which wins metals from cores, or which melts, treats or refines scrap metals and alloys for further use.

Smelting
A metallurgical thermal process in which a metal is separated in fused form from nonmetallic materials or other undesired metals with which it is associated.

Smoke
A type of emission resulting from incomplete combustion and consisting predominantly of small gas borne particles of combustible material present in sufficient quantity to be observable independently of the presence of other solids in the gas stream.

Snag
Removal of fins and rough places on a casting by means of grinding. See Casting, Fins, Grinding.

Snap Flask
A flask that has hinges and latches so that it may be removed from the mold prior to the pouring.

Soaking
Prolonged heating of a metal, furnace or ladle at a selected temperature.

Sodium Silicate (CO2 Process)
Molding sand is mixed with sodium silicate and the mould is gassed with carbon dioxide gas to produce a hard mold or core. See Water Glass.

Softening
A process used to soften metals through annealing or tempering. See Annealing.

Sold
That material which has a tendency to resist any attempt to change its size or shape.

Soldering
Joining metals by fusion of alloys that have relatively low melting points- most commonly, lead-based or tin-based alloys, which are the soft solders. Hard solders are alloys that have sliver, copper, or nickel bases, and use of these alloys with melting points higher than 800°F (426.7°C) is generally termed brazing. The sticking or adhering of molten metal to portions of a die.

Soldiers
Wooden pegs used to reinforce a body of sand or hold it in place.

Solid Contraction
Shrinkage or contraction as a metal cools from the solidifying temperature to room temperature.

Solid Solution
A single solid homogeneous crystalline phase containing two or more chemical species.

Solidification
Process of metal (or alloy) changing from the liquid to the solid state.

Solidification Range
Only pure metals solidify or freeze at one definite temperature. Alloys contain different constituents which solidify at different temperatures, and the various temperatures from that of the first constituent to solidify to that of the last to constituent to freeze is called the solidification range. See Solidification.

Solidification, Shrinkage
The decrease in size accompanying the freezing of a molten metal.

Solidifying Contraction
Shrinkage or contraction as metal solidifies. See Shrinkage.

Solidus
Temperature at which freezing is completed. Below that temperature all metals are completely solid.

Sonic Testing
Using sound waves above audible frequency via a supersonic reflectoscope to measure time sound waves take returning from opposite sides of casting. Defects return the waves in more or less time. See Defects.

Sorbite
Tempered martensite that has a micro-structure of distinctly granular appearance. Further tempering causes the appearance of clearly resolvable carbide particles (spheroidite).

Spalling
Buckling or flaking off of the surface material.

Spary Quenching
After solution heat treating, a mode of quenching in which a spray of water is directed upon material just removed from the furnace.

Specific Gravity
A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water at 39°F (3.9°C), for which the specific gravity is taken as 1,000 kg/m3. See Density.

Specific Heat
Equivalent to thermal capacity, or the quantity of heat required to produce a unit change in the temperature of a unit mass.

Specific Volume
Volume of one gram of a substance at a specific temperature, usually 68°F (20°C).

Spect-O-Graph
Optical instrument for determining the concentration of metallic constituents in a metal (or alloy) by the intensity of specific wavelengths generated when the metal or alloy is thermally or electrically excited.

Spectography
Process for determining the concentration of metallic constituents in a metal or alloy by the intensity of specific wavelengths generated when the metal or alloy is thermally or electrically excited.

Spheroidite
A cementite aggregate of globular carbide and ferrite.

Spheroidized Vementite (Divorced Pearlite)
The globular condition of iron carbide after a spheroidizing treatment.

Spiegeleisen (Spiegel)
Alloy of iron and manganese used in basic and acid open hearth steelmaking practice A high manganese pig iron containing 15-30% manganese and used in bessemer and open-hearth steel production. See Pig Iron.

Spiral Test
A method of interpreting the fluidity of an alloy by pouring molten metal into a mold with a long narrow channel. The length of such casting, under standardized conditions, is taken as the fluidity index of that alloy.

Splash Core
A core of tile placed in a mold to prevent erosion of the mold at places where metal impinges with more than normal force. Splash cores are commonly used at the bottom of large rammed pouring basins, at the bottom of long downsprues, or at the ingates of large molds.

Split Pattern
A pattern that is parted for convenience in molding.

Spongy Casting
A casting in which the metal is porous and dendritic.

Spout
A trough through which the metal flows from the furnace to the ladle.

Sprue
A vertical passageway that takes the molten metal from the pouring basin to the runner. See Runners.

Sprue (Downsprue Downgate)
(1) The channel, usually vertical, which the molten metal enters: so-called because it conducts metal down into the mold. (2) The vertical channel connecting the pouring basin with the runner system and terminates in the sprue well at the bottom. See Runners.

Sprue Base (or well)
Rectangular or cylindrical block that receives metal from the Sprue, reduces the velocity of the falling stream of metal and provides the transition from the vertical to the horizontal and send the metal into the runner system. See Runners.

Sprue Bottom
A print attached to the top or squeeze board of a mold to make an impression in the cope indicating where the sprue should be cut. See Cope, Molds.

Sprue Cutter
A metal tool used in cutting the pouring aperture, the sprue hole.

Sprue Hole
The opening through which the metal is poured into the cope to run into the casting cavity. See Cope.

Sprue Pin
In die-casting, a tapered pin with a rounded end projecting into a sprue hole, acting as a core that deflects the metal and aids in removal of the sprue from the die-casting. See Core, Sprue Hole.

Sprue Plug
A tapered metal or wood pin used to form the sprue opening in a mold. Also a metal or other stopper used in pouring basin to prevent molten metal from flowing into the sprue until a certain level has been reached. It prevents entry of dirt and dross. See Dross.

Spruing
Removing gates and risers from castings after the metal has solidified.

Squeeze Board
A board used on the cope half of the mold to permit squeezing of the mold.

Squeeze Head
In certain type of molding machines, a stationary or movable plate against which a filled mold is compressed, in order to complete the compacting of the sand.

Squeeze Pressure
The pressure applied by a molding machine to press the flask and contained sand against the fixed squeeze head or board on a molding machine.

Squeezer Machine
A power-operated, usually pneumatic, device used to pack sand into a flask. See Flask.

Stack Molding
Molding method in which the half-mold forms the cope and drag. They are placed one on top of the other and poured through a common sprue. Cavities on the bottom side of one half-mold rest on the flat side of the half-mold beneath. When the cavities are in both sides of the half-molds, the method is called multiple molding. See Multiple Mold.

Stainless Steel
A wide range of steels containing chromium or chromium and nickel, exhibiting high resistance to corrosion.

Standard Deviation
A statistical quantity used to describe the variation of a measurable attribute about some average value.

Standard Pattern
A pattern of high-grade material and workmanship in daily use or at frequent intervals. A pattern used as a master to make or check production patterns.

Standard Samples
A sample of know composition used to calibrate an instrument or method of analysis.

Standard Shapes
Refractory units stocked by manufacturers or made from stock molds.

Stave Construction
Attaching staves to polygonshaped heads in the building of cylindrical bodies; also, standard method used in making semicircular core boxes.

Steel
An alloy of iron and carbon, containing no more than 1.74% carbon. It must be malleable at some temperature while in the as-cast state. See As-Cast.

Steels, SAE
Common designation for the standard grades of steel approved by the Society of Automotive Engineers.

Steeped Construction
In patternmaking, the courses of material that when fastened together resemble steps. See Pattern.

Stellite
Proprietary name of a group of complex alloys retaining their hardness strength and resistance to oxidation at high temperatures; contains W, Co, Cr and C.

Step Gate
A vertical sprue containing a number of side branches or entries at different levels into the casting cavity. See Cavity, Gates, Sprue.

Stereolithography Apparatus (SLA)
Equipment used for computerized building of three-dimensional models and patterns. Enables the data representation of a CAD solid model to be directly converted into a plastic model of a casting.

Sticker
A lump on the surface of a casting caused by a portion of the mold face sticking to the pattern. Also, a forming tool used in molding.

Stock Allowance
Material added to a part to allow for surface preparation or precise dimensioning by machining.

Stock Cores
Standard cores of common diameters which are kept "in stock" for general use. See Cores.

Stool
Device used on molding machine to hold pattern plate or refractory block used to support a crucible in a crucible furnace. See Crucible, Crucible Furnace.

Stool Plate
Plate on a mold machine on which stools are mounted.

Stooling
Supporting green sand cores in machine molding while pattern is being withdrawn. See Green Sand, Core.

Stop Off
To shorten or change a mold.

Stop Off Strip
Reinforcing members on frail patterns. Impressions later filled with sand.

Stopper Head
A refractory shape at the end of a stopper rod, usually clay and graphite, seated in a ladle's nozzle.

Stopper Rod
A device in a bottom-pour ladle for controlling the flow of metal through the nozzle into the casting. The stopper rod consists of a steel rod, protecting sleeves, and a graphite stopper head. It may also be a single piece manufactured from graphite.

Stopping Off
Closing off a part of the mold that is not wanted to be cast.

Strained Casting
A phrase used to describe the result when molten metal is poured into the mold at too fast a rate or under too great metallstatic pressure, causing the cope to rise slightly from the drag and resulting in an oversize casting. See Casting, Cope, Drag, Mold.

Strainer Core
A perforated core placed at the bottom of a sprue or in other locations in the grating system to control the flow of the molten metal. To some extent, it prevents coarse particles of slag and dross from entering the mold cavity. See Core Strainer.

Strains, Casting
Strains produced by internal stresses, resulting from unequal contraction of the metal as the casting cools.

Streamline Flow
Steady flow of liquid without turbulence. Generally, not experienced in metal casting.

Strength, Baked
Compressive, shear, tensile, or transverse strength of a molded sand mixture when baked at a temperature above 230°F (110°C) and then cooled to room temperature.

Strength, Compressive
See Compressive Strength.

Strength, Impact
See Impact Strength.

Strength, Retained
Compressive, shear, tensile, or transverse strength attained by a sand mixture after being subjected to a cycle or cycles of heating and cooling which approximate foundry practice.

Strength, Shear
See Shear Strength.

Strength, Tensile
See Tensile Strength

Strength, Yield
See Yield Strength.

Stress Raisers
Factors such as sharp changes in contour or surface defects which concentrate stresses locally. See Defects.

Stress, Relieving
A heat treatment to reduce residual stresses followed by sufficiently slow cooling to minimize development of new residual stresses. See Heat Treatment.

Stress, Residual
Those stresses setup up in a metal as a result of nonuniform plastic deformation or the unequal cooling of a casting.

Stress-Corrosion Cracking
Spontaneous failure of metals by cracking under combined conditions of corrosion and stress, either residual or applied.

Strike Off (noun)
A straight edge, or metal bar, to cut the sand level with the top of the drag or cope flask. See Cope, Drag, Flask.

Strike Off (verb)
Operation of removing excess sand from top of core box or flask. See Core Box, Flask.

Stripper Pins
On certain molding machines, a series of pins (usually four in number) which support the rammed flask-half at the parting surface so that the mounted pattern may be drawn by lowering.

Stripping
Removing the pattern from the mold or core from core box. See Core, Core Box, Mold, Pattern.

Stripping Machine
A device for removing the pattern from a mold or a core from the core box.

Stripping Plate
A plate, formed to the contour of the pattern, which holds the sand in place while the pattern is drawn through the plate.

Stripping Time
In oil-oxygen and nobake mixture, the moment when the core box may be satisfactorily drawn from the core, or pattern from the sand.

Structure (Cast Structure)
The size and disposition of the constituents of a metal as cast.

Styroform Pattern
Expendable pattern of foamed plastic, especially polystyrene, use in manufacturing casting by the Full Mold process.

Subcutaneous Blowhole
Blowholes at or near the surface of solidified metal, covered with a thin layer of metal. May also be called pinhole porosity.

Subzero Treatment
Refrigeration of steel to promote transformation of retained austenite.

Sulfur
A nonmetallic chemical element, with a melting point of 444°C (831.2°F) occurring as an undesirable tramp (trace) element in most ferrous alloys.

Sulfur Prints
A macrographic method of examining for the distribution of sulfide impurities, in which a sheet of wet acidified bromide paper is placed on the polished surface to be examined.

Superalloy
An alloy developed for very high temperature use where relatively high stresses are encountered and where oxidation resistance is needed. See Alloy.

Supercooling
Lowering the temperature of a molten metal below its liquidus during cooling. See Liquidus.

Superduty Fireclay Brick
Having pce above 33 with less than 1.0 percent linear shrink in the 1599°C (2910°F) reheat test, and less than 4.0 percent loss in panel spalling test preheated at 1649°C (3000°F).

Superheat
Any increment of temperature above the melting point of a metal; sometimes construed to be any increment of temperature above normal casting temperatures introduced for the purpose of refining, alloying or improving fluidity.

Superheating
Theoretically, the temperature above the liquidus. In practice, it usually means temperature above the usual pouring range. See Liquidus.

Supersaturated
Metastable solution in which the dissolved material exceeds the amount the solvent can hold in normal equilibrium at the temperature and under the other conditions that prevail.

Supersonic Reflectoscope
An instrument for sending, receiving, and measuring sound waves over 20,000 cycles per second.

Supramor
An electromagnetic flaw detection ink for the rapid detection of subcutaneous and surface flaws in ferrous metals.

Surface Finish
Condition or appearance of the surface of a casting.

Surface Hardening
Conferring a superficial hardness to a steel while maintaining a relatively soft core. See Hardening.

Surface Protection Air Liquide (SPAL)
The use of liquid argon, liquid nitrogen, or carbon dioxide snow to minimize the reaction of air and molten metal that normally occurs in an induction furnace. The liquid or snow is fed onto the surface of the molten metal where it vaporizes, displacing the air thus reducing slag and oxygen levels.

Surface Texture
The roughness, waviness, lay or other characteristics of the surface of a part.

Surfacing
Depositing a filer metal on a metal surface by any method to obtain certain desired properties or dimensions.

Sweep (verb)
To form a mold or core by scraping the sand with a form sweep having the desired profile. See See Core, Mold.

Sweep or Skree (noun)
A board shaped to a required profile. It is used to remove excess material from a mold or core. See Core, Mold.

Sweep Work
Forming molds or cores by the use of jigs or templates instead of patterns. See Core, Jigs, Mold, Patterns.

Swell
A casting defect consisting of an increase in metal section due to the displacement of sand by metal pressure. See Defect.

Swing Frame Grinder
A device for grinding large castings where the work remains stationary. This grinder, too large to be hand lifted, is usually suspended from a hoist.

Synthetic Molding Sand
Any sand compounded from selected individual materials which, when mixed together, produce a mixture of the proper physical and mechanical properties from which to make foundry molds. See Molding Sand, Natural Sand.

Synthetic Sands
Synthetic mixture of silica sand and exact proportions of binders and additives instead of using natural sands. See Natural Sand.

System Sand
Foundry sand used in making molds and which eventually becomes the bulk of the sand used in the mechanical system or mechanized unit. See Sand.

Tap
To withdraw a molten charge from the melting unit.

Tap Hole
Opening in a furnace through which molten metal is tapped into the forehearth or ladle. See Ladle.

Teapot Ladle
Ladle with external spout wherein the molten metal is poured from the bottom rather than from the top. See Ladle.

Tear, Hot
Same meaning as hot crack, but developing before the casting has solidified completely. See Hot Crack.

Tear-Ups
Defect caused by backdraft, damaged pattern or uneven drawing of pattern. See Defect.

Telltale
Any distinguishing mark, projection, groove, etc. on a pattern, core box, mold or core which acts as a guide mark for assembling matching parts. See Core, Core Box, Mold.

Temper
Reheating hardened, normalized or mechanically worked steel to a temperature below the critical range to soften it and improve impact strength. The moisture content of a sand at which any certain physical test value is obtained, i.e., temper with respect to green compressive strength, permeability, retained compressive strength, etc. To mix material with enough liquid to develop desired molding properties.

Temper Brittleness
Brittleness that results when certain steels are held within or cooled slowly through a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at room temperature or lower temperatures.

Temper Carbon
Carbon in nodular form, characteristic of malleable iron.

Temper Stressing
Quenching in water from the tempering temperature to improve fatigue strength.

Temperature
Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales, as Centigrade, Fahrenheit, etc.

Temperature, Holding
Temperature above the critical phase transformation range at which castings are held as a part of the heat treatment cycle. The temperature maintained when metal is held in a furnace, usually prior to pouring.

Temperature, Pouring
The temperature of the metal as it is poured into the mold.

Tempered Martensite
Martensite that has been heated to produce to BCC iron and a fine dispersion of iron carbide. See Martensite.

Tempering (Sand)
Addition of water to and mixing molding sand to obtain uniform distribution of moisture. See Molding Sand.

Tensile Strength (Ultimate Tensile Strength, UTS)
A measure of the amount of mechanical stress a material can withstand before it fractures. Measured in pounds per square inch (PSI), or thousands of pounds per square inch (KSI).

Ternary Alloy
An alloy that contains three principal elements.

Test Bar
Standard specimen bar designed to permit determination of mechanical properties of the metal from which it was poured.

Test Lug
A lug cast as a part of the casting and later removed for testing purposes.

Thermal Conductivity
The property of matter by which heat energy is transmitted through particles in contact. For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree Fahrenheit, and for a thickness of one inch, Btu/hr•ft•F/in.

Thermal Contraction
The decrease in a linear dimension and volume of a material accompanying a change of temperature.

Thermal Expansion
The increase in a linear dimension and volume of a material accompanying a change of temperature.

Thermal Fatigue
Failure resulting from rapid cycles of alternate heating and cooling.

Thermal Shock
Stress developed by rapid and uneven heating of a material.

Thermal Spalling
Breaking up of refractory from stresses which arise during repeated heating and cooling.

Thermal Stability
Resistance of a material to drastic changes in temperature.

Thermit Reaction
Exothermic, self-propagating processes in which finely divided aluminum powder is used to reduce metal oxides to free metals by direct oxidation of aluminum to aluminum oxide, with accompanying reduction of the less stable metal oxide. See Exothermic Reaction, Endothermic Reaction.

Thermocouple
A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential which varies with the temperature of the junction. Thermocouples are used to operate temperature indicators or heat controls.

Thermography
The technique of obtaining a photographic record of heat distribution in a solid or fluid.

Tie Bar
Rod-bar or rod-shaped part of the casting added to prevent distortion caused by uneven contraction between separated members.

Tight Flask
A type of flask which remains on mold during pouring. Lugs are normally provided for clamping cope and drag together for pouring. See Cope, Drag, Flask.

Tin
A chemical element having symbol Sn, formula weight 118.70, specific gravity 7.31, and melting point 231.85°C.

Tin Sweat
Beads or exudations of a tin-rich low-melting phase found on the surface of or on risers of bronze castings, which are usually caused from absorption of hydrogen by the molten metal.

Titanium
A white metallic element, melting point 1660°C (3020°F), having a high strength-to-weight ratio; useful in aircraft parts.

Tolerance
The permissible deviation of a dimension from the nominal or desired value. Minimum clearance between mating parts.

Tongs
Metal instrument with two legs joined by a hinger for grasping and holding things, e.g., crucible tongs.

Tool Steel
Any high-carbon or alloy steel used to make a cutting tool for machining metals and for metal-casting dies.

Tooling Points
The fixed positions on the casting surfaces used for references during layout and machining.

Top Board
A wood board on the cope half of the mold to permit squeezing the mold. See Squeeze Board.

Toughness
The ability of the metal to absorb energy and to deform plastically during fracture. Toughness values obtained in testing depend upon the test temperature, the rate of loading, the size of the test specimen, as well as the presence of a notch and its acuity.

Tower Oven
Vertical, continuous core oven with suspended shelves attached to sprocket-driven chains.

Tramp Element (Trace)
Contaminant in the components of a furnace charge, or in the molten metal or casting, whose presence is felt to be either unimportant or undesirable to the quality of the casting.

Transfer Ladle
A ladle that may be supported on a monorail or carried in a shank and used to transfer metal from the melting furnace to the holding furnace or from furnace to pouring ladles. See Ladle, Shank.

Transformation (Temperature) Range
The critical temperature at which a change in phase occurs. To distinguish between the critical points in heating and cooling those in heating are referred to as the Ac points (c for Chauffage or heating) and those in cooling, Ar (r for Refroidissement).

Trim Die
Die for shearing (or shaving) flash from a die-casting.

Trimming
Removing fins, gates, etc. from castings. See Casting, Gate, Fins.

Trowel
Tool for sleeking, patching, and finishing a mold.

Tucking
Manual pressing of sand under the flask bars, in pockets and around gaggers where ramming alone fails to give desired density to ensure firm placement. See Sand, Ramming, Flask.

Tumbling Barrel
A revolving metal, wood box, or barrel in which castings are cleaned.

Tungsten
Steel-gray, metallic element, mp 3380°C (6116°F) used for electric lamp filament, x-ray tube target, and as alloy element in high-speed steels.

Turntable
The base on which a centrifugal casting mold rests.

Tuyere
Opening in the cupola where the air blast enters. See Cupola.

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