O - Chemical symbol for Oxygen

Occlusion - A term applied in the case of metals to the absorption or entrapment of gases.

O-Ring - A flexible 'O' shaped seal.

OCTG - includes casing, drill pipe and oil well tubing, which, depending on their use, may be formed through welded or seamless processes.

OD - Outside diameter

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

Off Center - Not centered; offset,eccentric or inaccurate.

Off Gauge - A defect referring to a variation of offset of the thickness of the plate from the designated aim gauge thickness and tolerance.

Off Gauge Reel - Reel onto which all the off-gauge and defective material is wound.

Off Iron - Pig iron not of the desired composition.

Off Line - Term that means a boiler or system is "not in use"

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-Size - Rolled steel too light or too heavy to meet requirements.

Offset - When a coil sidewall is winding up straight and suddenly moves in or out to another position and then continuing to wind up straight.

Offset Dial - Device used on #4 Side Trimmer askania. Movement of this dial changes the tracking of the line.

Offsetting - A coating defect consisting of a transference of smearing of ink or coating or other substance from the surface of one sheet of coated substrate to the back of the next sheet in a stack.

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 Cooler - Water cooled heat exchanger used to maintain the oil temperature on the feedwater pumps.

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

Oil Country Tubular Goods (OCTG) - Label applied to the pipe products used by petroleum exploration customers.

Oil Film Weight - Measure of the amount of oil applied to a flat rolled steel product; for Tin Mill Products, the measure is grams/base box; for Sheet Products, the measure is oz./sq.ft. (or gm./sq.m.).

Oil Hardening Steel - Used to describe tool or alloy steels where oil is used as the quenching medium in the hardening process.

Oil Quenching - "Quenching in oil. See Quenching "

Oil Sample - A small amount (at least 50 ml) of oil taken from a system in order to be tested.

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 Stain Aluminum - Stain produced by the incomplete burning of the lubricants on the surface of the sheet. Rolling subsequent to staining will change color from darker browns to lighter browns down to white.

Oil Stones - Molded abrasives in various shapes used to hand-sharpen cutting tools.

Oil Test - Test performed by the Met. Lab to check the amount of oil applied to strip.

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

Oiled - A product to which oil has been applied to retard rusting.

Oiling - The application of a surface layer of lubricant intended to retard rusting on sheet products and lubrication on Tin Mill products.

OIT - (Operator Interface Terminal) Terminal which displays the line-up, coils running on both reels, and the location of the weld.

Old Blowing Room - Used when the river water gets too cold.

Oleoresinous - A resin containing both oils and resins which cures by the oxidation process.

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.

Olsen (Ductility) Test - A method of measuring the ductility and drawing properties of strip or sheet metal which involves determination of the width and depth of impression. The test simulating a deep drawing operation is made by a standard steel ball under pressure, continuing until the cup formed from the metal sample fractures. Readings are in thousandths of an inch. This test is sometimes used to detect stretcher straining and indicates the surface finish after drawing, similar to the Erichsen ductility test.

On Cast - When the furnace is tapping out iron and maintaining full wind.

On Check - A term used when the furnace has pulled wind after casting to plug the hole.

On Line Term - Term which means a boiler or system is "in use".

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.

One-Side Bright Mill Finish - Sheet material having a moderate degree of brightness on one side. The reverse side is uncontrolled and may have a dull, non-uniform appearance.

OPEB Expense - Other Postretirement Employment Benefits. Usually refers to health care obligations to a mill's retired workers, although its meaning also can include layoff benefits (see FAS 106).

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 Hearth Furnace - A broad, shallow hearth to refine pig iron and scrap into steel. Heat is supplied from a large, luminous flame over the surface, and the refining takes seven to nine hours. Open Hearths, at one time the most abundant steelmaking furnaces among integrated companies, have been replaced by the basic oxygen furnace.

Open Hearth Line - An alternate water supply line from the Old Blowing Room Pump Room to the Old Blowing Room used when the river water gets too cold.

Open Line - Usually a steel-making defect, an open line refers to a line down the length of the strip caused by unknown conditions.

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.

Open-Hearth Process - Process of making steel by heating the metal in the hearth of a regenerative furnace. In the basic open-hearth steel process, the lining of the hearth is basic, usually magnesite; whereas in the acid open-hearth steel process, an acid material, silica, is used as the furnace lining and pig iron, extremely low in phosphorous (less than 0.04%), is the raw material charged in.

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.

Operating Rates - The ratio of raw steel production to the mill's stated capacity. Each December, steel companies report to the AISI their estimated capacity (if they could sell all steel they produced) for the following year, adjusted for any facility downtime.

Operator Side - The side of the strip that is nearest to the operator pulpit.

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.

Options - A choice to buy or sell metal at an agreed-upon price for a specific date. You must pay a premium (See Put and Call).

Orange Peel (effect) - A surface roughening (defect) encountered in forming products from metal stock that has a coarse grain size. It is due to uneven flow or to the appearance of the overly large grains usually the result of annealing at too high a temperature. Also referred to as pebbles and alligator skin.

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.

Order Matte - Individual description of the orders to be processed (issued by Production Planning). Also called 'mat' or 'mill order paper'.

Order Rate - The ratio of new orders recorded to the mill's capacity to produce the steel to fill the orders. Many analysts view trends in the order rate asharbingers of future production levels.

Ore - An iron bearing material used primarily in the blast furnace.

Organosol - Organosols contain poly-vinyl chloride (PVC) dispersed in solvents. At temperatures of 325-350 B0 F (165-175 B0 Centegrade) the vinyl particles coalesce and dissolve in the plasticizers to form homogeneous films with good hardness, toughness and adhesion.

Orientation (crystal) - Arrangement of certain crystal axes or crystal planes in a crystalline aggregate with respect to a given direction or plane. If there is any tendency for one arrangement to predominate, it is known as the preferred orientation; in the absence of any such preference, random orientation exists.

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.

Os - Chemical symbol for osmium.

Oscillated Wound or Scroll Wound - A method of even winding metal strip or wire on to a reel or mandrel wherein the strands are uniformly over-lapped. Sometimes termed stagger wound or vibrated wound. The opposite of ribbon wound.

Oscillate Wound/Ribbon Wound - Oscillate winding is a technique that ws develooped to aid in winding and shipping customer orders for multiples. (Multiples are created by slitting or shearing a coil into any width or set of widths) The slits are wound back and forth on a mandrel in the same manner that a fishing line is taken up on a reel; that is left to right, right to left, left to right. This allows for multiples to be wrapped on one wide coil that is easily handled in shipping.

Oscillating - A method of winding narrow strip steel over a much wider roll. Customers want to have as much steel on a coil as will fit in their machines, so they can spend less time moving the material and more time using it. By coiling the strip like fishing line (or thread) over a spool, a much longer strip can fit onto a coil of proper diameter. Oscillate-wound coils allow the customer to enjoy longer processing runs.

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

Osmium - Chemical symbol Os. A bluish-white metal that is so hard it is difficult to fabricate.

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

Ottowa Sand - A sand originating near Ottawa Ill., also know as St. Peter sandstone.

Out of Register - An embossed pattern distortion due to misalignment of the male and female embossing rolls

Outboard Bearing - Pump bearing that is furthest from the driver.

Outlet - Outlet valve from auto valve or tank.

Ovality - Deviation from a circular periphery, usually expressed as the total difference found at any one cross section between the individual maximum and minimum diameters, which usually occur at or about 90 degrees

Oval - A hot-rolled carbon steel bar product which is oval in cross section.

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.

Overarm - The support for the end of a milling cutter which is on the opposite side of the cutter from the spindle and column.

Overfill - A defect in a rolled bar or other section which is an over-fullness on some part of the surface. Among the causes are worn rolls and extrusion into the clearance of the rolls.

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.

Overhead Separators - Used when producing mults on a slitting unit; disks which make an alley for each strip to go through while being coiled.

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.

Overheating - Can occur in preheat furnaces prior to forging or in the heat-treating operation. The condition results when metal temperature exceeds the critical temperature of the alloy involved and a change in phase occurs; this is also known as the transformation temperature. Externally, overheated material will often form blisters or a web of fine cracks; internally, overheating causes precipitation of melted constituents around grain boundries and the formation or rounded pools of melted constituents often called �rosettes�.

Overpickled - Reject caused by the strip laying in acid for a period of time.

Overspeed Trip - (On steam pumps) A device that trips the turbine on a steam pump if the prime is lost and the pump overspeeds.

Overspeed Trip Switch - Spring loaded stop valve which is connected to a turbine governor by a linkage rod that will stop the flow of steam to a turbine.

Overstressing - Permanently deforming a metal by subjecting it to stresses that exceed the elastic limit.

Overwidth - Product whose width is above the customer's finished width tolerance.

Overwind - Steel strip that comes off of the top of the coil on the entry reel into the side trimmer.

Overwrap - The direction which a coil is wrapped or unwrapped. If coil is being overwrapped a reel is turning and steel is being fed from TOP.

Owen Jet Dust Counter - An instrument similar to the Konimeter, using the humidification factor.

Oxidation - The addition of oxygen to a compound. Exposure to atmosphere sometimes results in oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase.

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.

Oxide Discoloration - See �Stain, Heat Treat�.

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.

Oxy-Acetylene Welding - A process for joining two pieces of metal in which the required high temperature is obtained by the combustion of acetylene gas and oxygen. The gases are thoroughly mixed in the nozzle or tip of the welding torch to ensure perfect combustion. The weld may be formed directly between two adjoining surfaces, but usually metal from a welding rod is fused in between the surfaces of the joint.

Oxygen - Oxygen is one of the chief constituents of the atmosphere of which it forms approximately on fifth. It is odorless and invisible. Although oxygen itself does not burn, it is extremely efficient in supporting combustion, nearly all other chemical elements

Oxygen Blow - (O2 blow) Steel making period when oxygen is introduced into the furnace vessel of scrap metal and blast furnace hot metal.

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.

Oil Hardening - A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and quenching in oil.

Oil-Hardening Steel - Steel adaptable to hardening by heat treatment and quenching in oil.

Open Surface - Rough surface on black plate, sheet or strip, resulting from imperfection in the original steel bars from which the plate was rolled.

Open-Hearth Furnace - A reverberatory melting furnace with a shallow hearth and a low roof. The flame passes over the charge in the hearth, causing the charge to be heated both by direct flame and radiation from the roof and sidewalls of the furnace. In ferrous industry, the furnace is regenerative.

Orange Peel - A pebble-grain surface which develops in forming of metals having coarse grains.

Ore - A mineral from which metal is (or may be) extracted.

Orientation (crystal) - Directions in space of the axes of the lattice of a crystal with respect to a chosen reference or coordinate system.

Overaging - Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property, so that the property is altered in the direction of the initial value.

Overaging - Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property.

Overaging - Aging under conditions of time and temperature greater than those required to obtain maximum strength.

Overheating - Heating a metal or alloy to such a high temperature that its properties are impaired. When the original properties cannot be restored by further heat treating, by mechanical working, or by combination of working and heat treating, the overheating is known as burning.

Overheating - Heating a metal or alloy to such a high temperature that its properties are impaired. When the original properties cannot be restored by further heat treating, by mechanical working or by a combination of working and heat treating, the overheating is known as burning.

Oxidation - (1) A reaction in which there is an increase in valence resulting from a loss of electrons. (2) Chemical combination with oxygen to form an oxide.

Oxide - Compound of oxygen with another element.

Oxidized Surface - A surface having a thin, tightly adhering oxidized skin.

Oxygen Lance - A length of pipe used to convey oxygen onto a bath of molten metal.

Oxygen-Free Copper - Electrolytic copper free from cuprous oxide, produced without the use of residual metallic or metalloidal deoxidizers.