Atlas Foundry Company - logo  
Atlas Foundry home About Atlas Foundry Foundry glossary Site map Contact Atlas Foundry
Atlas Foundry Company - logo  
Atlas Foundry Company - Since 1893 Gray Iron Casting Services Foundry products Equipment Benefits Frequently asked questions (FAQs) Tips and facts Links
Foundry - photo
Foundry glossary
Call Atlas Foundry for Gray Iron Casting Services at 765-662-2525
ISO9001:2015 Certified

Find us on FaceBook
Follow Us on LinkedIN

Home > Glossary of Foundry Terms > O

Glossary of Foundry Terms - O

A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | XYZ


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.


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.


(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.


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.


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.



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


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.


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.


See Continuous Annealing Furnace.


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


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.


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.


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


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.


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.


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.


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.


A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | XYZ

If you would more information about Atlas Foundry Company and the Gray Iron Casting and other services we provide, please call us at (765) 662-2525, fill out our Information Request Form , or email Sales.

Services | Products | Equipment | Benefits | FAQs
Tips & Facts | Links | About Atlas Foundry | Foundry Glossary
Contact Atlas Foundry | Site Map | Back to Home

Atlas Foundry Company, Inc.
601 N. Henderson Avenue
Marion, IN 46952-3348
Telephone: (765) 662-2525 • Fax: (765) 662-2902
Email: Atlas Foundry • Sales: Email Sales