Semi-permanent molds of plaster of paris, graphite, or dry sand, tarred and dried and used for repetitive work in the foundry.
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.
Core defect caused by improper gagging of dimensions.
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.
A core bonded with oil.
A mold in which the sand is bonded by an oil binder.
Furnaces fired with oil.
Quenching in oil. See Quenching.
Oil Sand Core
Core in which sand mass is bound by an oil-based binder.
Sand bonded with such oils as linseed and the synthetics.
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.
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.
Riser whose top is open to the atmosphere through the top of the mold. See Riser.
A casting poured into a mold which has no cope or other covering.
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.
Steel made in open-heart furnace.
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.
That moisture content which results in developing the maximum of any property of a sand mixture.
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.
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.
A sand originating near Ottawa, IL. Also know as St. Peter sandstone.
A furnace or oven for drying molds or cores.
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.
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.
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.
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.
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.
See Lance, Oxygen.