N - Chemical symbol for Nitrogen

Na - Chemical symbol for Sodium

Nb - Chemcial symbol for Niobium

NACE - National Association of Corrosion Engineers

Narrow - Product whose width is below the customer's finished width tolerance.

National Machine Tool Builders Association - The Association for Manufacturing Technology

Natural Aging - See Aging

Natural Sand - Unconsolidated sand, sand derived from a rock in which grains separate along their natural boundaries. This includes soft sandstone where little pressure is required to separate the individual grains.

Naturally Bonded Molding Sand - A sand containing sufficient bonding material as mined to be suitable for molding purposes. Seldom used today in the metalcasing industry.

Naval Brass(Admiralty Brass) - An alloy of copper,zinc and tin used widely in the marine industry because of resistance to saltwater corrosion;actually its bronze.

Navy (USA) Tear Test - A method of evaluating the susceptibility of ship plate to brittle or cleavage type fracture.

NBS - National Bureau of Standards

NDDT - Nil ductility transition temperature, determined in the dropweight test. Refers to the absence of the ductile fracture appearance and any reduction in area due to the brittle behavior of the steel.

Near-side - The free-side of the line (closest to the operator's pulpit).

Neat Brick - Brick with faces arranged so one of the flat faces in inclined toward the other, almost eliminating one end face.

Neat Cement - Portland Cement mixed with water only.

Neck Down (Knock-Off, Wafer Core, Washburn, Cameron Core) - "A thin core or tile used to restrict the riser neck, making it easier to break or cut off the riser from the casting. See Core "

Necking - Strip condition caused by the application of too much tension which causes the strip to become narrower (or stretched).

Necking Down - Reduction in area concentrated at the subsequent location of fracture when a ductile metal is stressed beyond it yield point in tension.

Necleus - The first structurally determinate particle of a new phase or structure that may be about to form. Applicable in particular to solidification, recrystallization, and transformations, in the solid state.

Needle Cutter Steel - Usually supplied quarter hard rolled, extra precision rolled with sheared edges. Carbon content 1.25 - Chromium .15. Usually supplied in a 2 width from .002 to .035. Used for cutting the eyes of needle and milling the latch in a latch needle.

Needle Valve - A high pressure shut off valve used on the hydraulic oil stands and manifolds. It usually uses some type of tool to manipulate or turn the valve's stem (clockwise to close, counterclockwise to open).

Needles - Elongated acicular crystals, tapering at each end to a fine point, as martensite.

Needling Agents - Special agents such a boron which markedly increase the hardness of steel.

Negative Quenching (Negative Hardening) - Accelerated cooling in water or oil, from a temperature below the critical range.

Negative Thermoie Heat Exchange - In shell molding, improving the mass-surface ratio by simulating profile geometry of pattern or core cavity on the underside; will boost running temperature of high projections by 25 percent.

Nerf wheel - Round foam wheel inserted into the core of a coil without an insert before the coil is put on the entry reel to support the inner laps of the coil.

Nesh (Hot Short) - A British term applied to metal that is weak and ruptures easily under not working conditions.

Nick Rolled products, see Scratch. Extrusions, see Mark, Handling. -

Neutral Refractories - A loose term designating refractories which presumably will not react with so-call acid or basic refractories and slags.

Neutron - Elementary nuclear particle with a mass (1.00893 mass units) approximately the same as that of a hydrogen atom. It is electrically neutral.

New Jersey Sand - A large number of grades of foundry sands mined in southern New Jersey.

Next Standard Operation - Indicates the next process for which the coil is normally scheduled. An example of a Next Standard Operation for a Pickler would be a Tandem Mill.

NFFS - Non-Ferrous Founder's Society

Ni - Chemical symbol for Nickel

Nichrome - Oxidation-resistant alloy 65% Ni, 20% Fe, and 15% Cr.

Nick Rolled products, see Scratch. Extrusions, see Mark, Handling. - NULL

Nickel - (Ni) An alloying element used as a raw material for certain classes of stainless steel. Nickel provides high degrees of ductility (ability to change shape without fracture) as well as resistance to corrosion. Approximately 65% of all nickel is used in the making of stainless steel.

Nickel-Based Superalloys - Multi-alloy metals suited for high-performance, high-temperature applications. These are nickel-iron-chrome al;loys (which also contain titanium,columbian and sluminum) and nickel-chrome-iron alloys (which often also contain molybdenum,tungsten,titanium,cobalt,aluminum and columbium).

Nickel Steel - Steel containing nickel as an alloying element. Varying amounts are added to increase the strength in the normalized condition to enable hardening to be performed in oil or air instead of water.

Nine-Inch Equivalent - Standard unit of volume in refractories industries; 9x4-1/2,2-1/2 in brick.

Niobium - (Chemical symbol Nb) Element No. 41 of the periodic system. See Columbium

Nipple - A pipe coupling consisting of a short piece of threaded tubing.

NISA - National Industrial Sand Association

Nital - A solution of nitric acid in alcohol use as an etching agent in ferrous metallography.

Nitrading - A case hardening process in which ammonia or some other form of nitrogen is introduced to the surface of certain alloys.

Nitriding - Process of surface hardening certain types of steel by heating in ammonia gas at about 935-1000 (degrees) F., the increase in hardness being the result of surface nitride formation. Certain alloying constituents, principal among them being aluminum, greatly facilitate the hardening reaction. In general, the depth of the case is less than with carburizing.

Nitriding Steel - Steel which is particularly suited for the nitriding process, that is, it will form a very hard and adherent surface upon proper nitriding (heating in a partially dissociated atmosphere of ammonia gas). Composition usually .20-.40 carbon, .90-1.50 chromium, .15-1.00 molybdenum, and .85-1.20% aluminum.

Nitrogen - Nitrogen is a gas that forms approximately 79% by volume or 77% by weight of the atmosphere. It can combine with many metals to form nitrides and is thus applied to the case-hardening of steel, the usual source for this purpose being ammmonia.

Nitrogen Back Up Air - A back up air supply for # 6 Turbo Blower.

Nitrogen Flush - Bubbling nitrogen gas through a metal melt under vacuum (as with valve bronze) to improve tensile properties and pressure tightness.

No Screw Plate - Steel that has not been rolled.

No. 1 Heavy Melt - Obsolete steel scrap grade, at least one-quarter inch in thickness and in sections no larger than five feet by two feet. Much of the metal comes from demolished buildings, truck frames and heavy duty springs. Mini-mills are primary consumers of No. 1 heavy scrap.

Nobake Binder - A synthetic liquid resin sand binder that hardens completely at room temperature, generally not requiring baking, used in Cold-Setting process.

Noble Metals - Metallic elements with surfaces that do not readily oxidize in air; e.g., gold, silver, platinum.

Nodular Fireclay (Burley, Burley Flint) - Rock containing aluminous or ferrogenous nodules, or both, bonded by fireclay.

Nodular Graphite - Graphite or carbon in modular form, characteristically in malleable and nodular iron.

Nodular Iron - Iron of a normally gray cast iron type that has been suitably treated with a nodularizing agent so that all or the major portion of its graphitic carbon has a nodular or spherulitic form as cast. Often referred to as Ductile Iron.

Noise Radiator - A device creating noise.

Noise Spectrum - The various frequencies making a noise.

Nomogram (Graph) - A graph that enables one by the aid of a straight-edge to read off the value of a dependent variable when the value of two or more independent variables are given.

Non-Aging - Little to no change in mechanical and physical properties over time; Yield point elongation is zero. See Aging.

Non-Ferrous Founders' Society - See Non-Ferrous Founder's Society for address information.

Non-Heat-Treatable Alloy - An alloy which can be strengthened only by cold work

Non-Refractory Alloy - A term opposed to refractory alloy. A non-refractory alloy has malleability, that is, ease of flattening when subjected to rolling or hammering.

Non-Return - A flapper check valve at the boiler steam exit that is used to isolate a down boiler and to prevent steam feedback during outage emergencies.

Non-Return Valve - Check valve located at the boiler steam exit which is used to isolate a down boiler and to prevent steam feedback during emergencies.

Non-Temper Passed Bands - Hot bands.

Nondestructive Testing (Inspection) - Testing or inspection that does not destroy the object being tested or inspected.

Nonfill - Failure of metal to fill a forging die impression.

Non Magnetic Steels - Austenitic steels such as the 14% manganese steels and the 303 type 18/8% chromium-nickel stainless steels.

Nonreflow Plate - (MATTE) Does not get reflowed to melt the Tin coating.

Normal Segregation - Concentration of alloying constituents that have low melting points in those portions of a casting that solidify last.

Normal Steel - Steel in which the pearlite is completely laminated.

Normalizing - Heating a ferrous alloy to a suitable temperature above the transformation temperature Ac3, followed by cooling at a suitable rate, usually in still air to a temperature substantially below the transformation range.

Notch Bar - Small size ingot with notches to facilitate breakage for remelting.

Notch Brittleness - A measure of the susceptibility of a material to brittle fracture at locations of stress concentration. For example, in a notch tensile test a material is said to be notch brittle if its notch strength is less than its tensile strength; otherwise, it is said to be notch ductile.

Notch, double Shear - An abrupt deviation from straight on a sheared edge. This offset may occur if the flat sheet or plate product is longer that the blade for the final shearing operation.

Notch Sensitivity - A measure of the reduction in strength of a metal caused by the presence of stress concentration. Values can be obtained from static, impact or fatigue tests.

Notched Bar - A test specimen which is notched. Used in impact or fatigue tests.

Notched Bar Test - A test to determine the resistance of a material to a suddenly applied stress, i.e. shock. A notched test piece is employed in an Izod or Charpy machine and the results are recorded in ft, lbs or Joules.

Novalak - A two-step basic flake resin with no thermosetting properties, applied to sand in shell molding process as a mold or solution.

Nozzle - Pouring spout of the bottom-pour ladle.

Nozzle Brick - A thick-walled tubular refractory shape set in bottom of a ladle through which steel is teemed.

Nozzle Pocket Brick - A refractory shape set in bottom of a ladle containing a recess in which nozzle is set.

NTP - Normal temperature and pressure reference point; zero centigrade 760mm mercury pressure.

NUE - Non-upset end OCTG tubing description (not as common as EUE)

Nucleation - 1) (homogeneous) the initiation of solid crystals from the liquid stage, or initiation of solid crystals from the liquid stage, or a new phase within a solid without outside interference - rarely occurs, 2) heterogeneous) foreign particles altering the liquid-solid interface energy during phase changes.

Nucleus - (1) The first structurally stable particle capable of initiating recrystallization of a phase or the growth of a new phase, and separated form the matrix by an interface. (2) The heavy central core of an atom, in which most of the mass and the total positive electrical charge are concentrated.

Number as Pertaining to Hardness - In copper base alloys inductry; temper is referred to as so many numbers hard, i.e. Yellow Brass Half Hard is termed 2 numbers hard. This term is derived from terminology used on the mill gloor where by temper or hardness is imparted by cold working and classified as to hardness by the number of Brown & Sharpe gages away from the soft or as-annealed state.

Natural Aging - Spontaneous aging of a supersaturated solid solution at room temperature.

Necking - Local reduction of the cross-sectional area of metal by stretching.

Network Structure - A structure in which the crystals of one constituent are surrounded by envelopes of another constituent which gives a network appearance to an etched test specimen.

Neumann Band - A mechanical (deformation) twin in ferrite.

Nickel - (Chemical symbol Ni) Element No. 28 of the periodic system; atomic weight 58.69. Silvery white, slightly magnetic metal, of medium hardness and high degree of ductility and malleability and resistance to chemical and atmospheric corrosion; melting point 2651 (degrees) F.; boiling point about 5250 (degrees) F., specific gravity 8.90. Used for electroplating. Used as an alloying agent, it is of great importance in iron-base alloys in stainless steels and in copper-base alloys such as Cupro-Nickel, as well as in nickel-base alloys such as Monel Metal. Its principal functions as an alloy in steel making: (1) Strengthens unquenched or annealed steels. (2) Toughens pearlitic-ferritic steels (especially at low temperature). (3) Renders high-chromium iron alloys austenitic.

Nickel Silver - Copper base alloys that contain 10-45% Zn. and 5-30% Ni.

Nitriding - Introducing nitrogen into a solid ferrous alloy by holding at a suitable temperature (below Ac1 for ferritic steels) in contact with a nitrogenous material, usually ammonia of molten cyanide of appropriate composition. Quenching is not required to produce a hard case.

Nodular Pearlite - Pearlite that has grown as a colony with an approximately spherical morphology.

Non-Ferrous Metals - Metals or alloys that are free of iron or comparatively so.

Non-Metallic Inclusions - Impurities (commonly oxides), sulphides, silicates or similar substances held in metals mechanically during solidification or formed by reactions in the solid state.

Non-Scalloping Quality Strip Steel - Strip steel ordered or sold on the basis of absence of unevenness, or ears, on the edges of the steel, when subjected to deep drawing.

Normalizing - Heating a ferrous alloy to a suitable temperature above A3 or Acm and then cooling in still air to a temperature substantially below A1. The cooling rate usually is in the range 900 to1800 F/h (500 to 1000C/h).

Normalizing - Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range.

Normalizing - A heat treatment applied to steel, Involves heating above the critical range followed by cooling in still air. Is performed to refine the crystal structure and eliminate internal stress.p>

Nucleation - Initiation of a phase transformation at discrete sites, the new phase growing from nuclei.

Number as Pertaining to Hardness - In copper base alloys inductry; temper is referred to as so many numbers hard, i.e. Yellow Brass Half Hard is termed 2 numbers hard. This term is derived from terminology used on the mill gloor where by temper or hardness is imparted by cold working and classified as to hardness by the number of Brown & Sharpe gages away from the soft or as-annealed state.