O

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

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

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

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

Off Iron:  Pig iron not of the desired composition.

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 or Mold: A core or mold in which the sand is bonded by an oil binder.

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.

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

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

Olivine: (Mg2Fe2 SiO4) A naturally occurring mineral composed of Fosterite and Fayalite, crushed and used as a molding sand.

One-Piece Pattern:  Solid pattern, not necessarily made from one piece of material. 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 came] back distributions.

Online: In EDP, operation of any input/output device as a component of a computer; under computer control; tied into a computer.

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.

Openhearth 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.

Open Riser: See Riser, Open.

Open Sand Casting: A casting produced in an open mold; poured in the drag, with no cope or other top covering.

Operand:  In EDP, any one of the quantities entering or arising in an operation; an argument parameter, result or indication of the location of the next instruction.

Operation, Fixed Cycle: In EDP, a computer performance in which a fixed time is allocated to an operation.

Operation, Realtime and Online: In EDP, processing data so that the results of the data-processing are useful to the physical operation; as a continuous castings, cleaning, etc., operation, receiving data of a defect in time to prevent its repetition.

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.

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.

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

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

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

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

Ottowa Sand: A sand originating near Ottawa, Ill., also known as St. Peter sandstone.

Output:  In EDP, information transferred from the internal storage of a computer through such output devices as printers and CRT’S.

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

Ovens: See Continuous Annealing Furnace.

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

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.

Overhang: 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.

Overheated: A term applied when, after exposure to an excessively high temperature, a metal develops an undesirably 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.

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

Oxidation: Any reaction of an element with oxygen. In a narrow sense, oxidation means the taking on of oxygen by an element or compound, and on the
basis of the electron theory it is a process in which an element loses electrons.

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.

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