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Home > Glossary of Foundry Terms > P

Glossary of Foundry Terms - P

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In production, the acceptable quality level.


In production, lot tolerance.

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.


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.


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.


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.


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.



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


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


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


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.


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.


Abbreviation for Pyrometric Cone Equivalent.


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.


Free removal of burnt molding sand from casting.


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.


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.


Natural magnesia in nodular form, formed by heating.


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.


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



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.


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.


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.


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."


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.


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.


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.



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.


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.


Powdered graphite.  See Printing Back.


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.


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.


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


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.


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.



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.


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.


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.


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.


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.



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.


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.


Abbreviation for pounds per square inch.


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.


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.


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


Chemical metallurgical process dependent upon heat.


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.


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


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Atlas Foundry Company, Inc.
601 N. Henderson Avenue
Marion, IN 46952-3348
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