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Oddsides
Semi-permanent 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 gagging 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 Quenching
Quenching in oil.
See Quenching
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.
Olive
(Mg2,Fe2SiO4) 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.
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 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.
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.
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.
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.
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 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.
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.
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 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