The InterWire Group · 355 Main Street · Armonk NY 10504

Glossary of Terms

Print PDF

Age Hardening Hardening by aging, usually after rapid cooling or cold working. See aging.
Aging In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures.
Alloy An alloy is a substance made by melting two or more elements together, at least one of them is a metal.
Annealing Heating to and holding at a suitable temperature and then cooling at a suitable rate, for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure or obtaining desired mechanical, physical or other properties. Any process of annealing will usually reduce stresses, but if the treatment is applied for the sole purpose of such relief it should be designated stress relieving.
ANSI American National Standards Institute
ASTM American Society for Testing and Materials
Bend Test A test for determining relative ductility of metal that is to be formed (usually sheet, strip, plate or wire) or for determining soundness and toughness of metal (after welding, for example) or twisting insulated wire around a mandrel or its own diameter to determine if the insulation will crack under such stress. The specimen is usually bent over a specified diameter through a specified angle for a specified number of cycles.
Block Steel drum shaped part of a wire draw machine.  The block size determines the ID and OD of the wire coil.
Bright Dawn Wire with no metallic surface coating such as zinc
Bull Block A large diameter drawing block used for producing large diameter wires.
Cable Multiple strands that are laid together helically and symmetrically arranged in multiple layers with uniform pitch or lay.
Cadmium Cadmium (Element 48) coated wire. Cadmium is a bluish white metal, considered a hazardous material, is NOT RoHS compliant.
Camber (1) Deviation from edge straightness usually referring to the greatest deviation of side edge from a straight line.
Carrier Also called a Rack, Stem, Spider or Top Hat. A tubular metal form used for producing large continuous coils or stacking mill coils for storage and transportation.
Cast The cast of the wire is the diameter of a circle it will make when cutting off several feet off the spool/coil.
Coils Wire wound into continuous, regularly spaced rings layered upon each other.
Cold Drawing Pulling wire at room temperature through a die, or series of dies, to reduce the diameter of the rod/wire. The cold working process increases both Yield and Tensile strengths.
Cold Rolling A metal forming process in which the metal stock is passed through one or more pairs of rolls to reduce diameter and/or shape.
Compression Spring A spring that is designed to compress when weight or force is applied to either the top or bottom of the spring.
Corrosion The deterioration of a metal by chemical or electrochemical reaction with its environment.
Decarburization Loss of carbon from the surface layer of a carbon containing alloy due to reaction with one or more chemical substances in a medium that contacts the surface.
Degreasing Removing oil or grease from a surface.
Density The weight of a metal, usually expressed in pounds per cubic inch or grams per cubic centimeter.
Diameter Tolerance Generally a plus and minus tolerance. Based upon the ASTM specification. Tighter tolerances may be requested when placing mill orders.
Die A perforated block through with metal is drawn through for reshaping and diameter change.
Die Lines Lines or markings on formed, drawn or extruded metal parts caused by imperfections in the surface of the die.
Drawability A measure of the workability of a metal subject to a drawing process.
Drawing Reducing the cross section area of wire or tubing by pulling it through a die.
Drawing Compound A substance applied to prevent pickup and scoring during drawing by preventing metal-to-metal contact of the work and die.
Ductility The ability of a material to deform without fracturing.
Eddy Current Testing An electromagnetic nondestructive testing method in which eddy-current flow is induced in the test object. Changes in the flow caused by variations in the object are reflected into a nearby coil or coils where they are detected and measured by suitable instrumentation.
Electroplating Electrodepositing metal (may be an alloy) in an adherent form upon an object serving as a cathode.
Electro-polishing A process that produces a shiny surface on stainless steel using an electro-chemical treatment.
Extension Spring A closely coiled spring made to resist a force pulling in the direction of its length. Also called Tension Spring.
Fatigue The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the tensile strength of the material. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress.
Fracture Test Breaking a specimen and examining the fractured surface with the unaided eye or with a low power microscope to determine such things as composition, grain size, case depth or soundness.
Full Hard A temper of nonferrous alloys corresponding approximately to a cold worked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following full annealing..
Galvanized Wire Ferrous (Carbon based) wire that has a protective zinc coating. This coating is added through electrochemical, electrodepositon or hot-dip galvanization. This is done to prevent rusting of a ferrous item.
Half-hard A temper of nonferrous alloys characterized by tensile strength about midway between those of dead soft and full hard tempers.
Hard Drawn Wire A general purpose carbon steel wire, used for low stress application. Bright hard drawn ASTM A-227. Galvanized hard drawn ASTM A-764.
Hardness Resistance of metal to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper, or to resistance to scratching, abrasion or cutting. Indentation hardness may be measured by various hardness tests, such as Brinell, Rockwell and Vickers.
Heat Number This number is assigned to the product of one melt. It is a unique identity code. Providing traceability from the melt through final part production.
Heat Treatment Heating and cooling a solid metal or alloy in such a way as to obtain desired conditions or properties.
Helix Spiral arrangement of one complete circular strand. Too much separation or cork screw from side to side may indicate a Bad Helix.
Inclusions Particles of foreign material in a metals. The particles are usually compounds (such as oxides, sulfides or silicates), but may be of any substance that is foreign to the matrix.
Liquor Finish A smooth, bright finish characteristic of wet-drawn wire when a liquor from fermented grain mash is used as a drawing lubricant..
Lubricant Any substance used to reduce friction between two surfaces in contact.
Mechanical Properties The properties of a material that reveal its elastic and inelastic behavior when force is applied, thereby indicating its suitability for mechanical applications; for example, tensile strength, elongation, hardness and fatigue limit.
Mechanical Testing Determination of mechanical properties.
Microstructure The structure of metals as revealed by microscopic examination of the etched surface of a polished specimen.
Music Wire Made of high carbon steel, also known as spring wire. Used in high stress applications, mechanical springs, and piano strings. Music wires may also be produced with zinc and other metal coatings. ASTM A-228.
Nickel Coating Nickel is a soft, metallic material that is an excellent lubricant for spring coiling. Stainless steel tends to be sticky during cold drawing, nickel coating these grades can enhance the surface quality.
Patenting Passing the wire through tubes in a furnace. The high temperature treatment produces the uniform austenite large grain size. The rapid cooling process in either air or lead, results in a very fine grain structure, with no separation of primary ferrite.
Passivation The changing of the chemically active surface of a metal to a much less reactive state.
Phosphate A coating used on steel wire for corrosion resistance, lubricant, or as a foundation for additional coating or painting.
Pickling Removing surface oxides from metals by chemical or electrochemical reaction.
Plating Forming an adherent layer of metal upon an object.
Precipitation Hardening This is a heat treatment technique which is used on some grades of stainless steel, as well as certain non-ferrous metals like aluminum, nickel and titanium. Its purpose is to significantly raise the strength and hardness of the metal, but the downside of using the process is a reduction in ductility.
Process Annealing In the sheet and wire industries, heating a ferrous alloy to a temperature close to, but below, the lower limit of the transformation range and then cooling in order to soften the alloy for further cold working.
PSI Pounds per square inch.
Reduction in Area (1) Commonly, the difference expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum cross-sectional area measured after complete separation.
Rockwell Hardness Test An indentation hardness test based on the depth of penetration of a specified penetrator into the specimen under certain arbitrarily fixed conditions. Not performed on wire.
Rod Raw material that the wire is drawn from. Rod is produced from a billet passed through a series of rolls at an elevated temperature, below the melting point, which reduces the cross-sectional area.
Rolling Reducing the cross-sectional area of metal stock, or otherwise shaping metal products, through the use of rotating rolls.
Scaling (1) Forming a thick layer of oxidation products on metals at high temperature.
Seam A linear, longitudinal crack in the bar, rod or wire. This occurs during the steelmaking process. Seams may be superficial and not affect the material performance, but they can also be severe and initiate fatigue cracking.
Shaped Wire General produced by cold rolling. Cross section that is other than round. Generally a flat, rectangle or square, oval, half-round, or wedge shape.
Soap Coat Used as a lubricant. Stainless steel wire can be produced with a non-metallic coating commonly referred to as soap coating. The actual coating varies between producing mills. This is the least expensive stainless coating.
Spring Back (1) The elastic recovery of metal after stressing. (2) The degree to which metal tends to return to its original shape or contour after undergoing a forming operation.
Stainless Steel Wire Various steels alloyed with at least 10% Chromium and other elements that are resistant to corrosion or rusting. Common wire alloys are: 302, 304/304L, 316/316L, and 17-7.
Spring Temper See temper.
Stress-Relief Annealing Heat treating the formed spring to, and if necessary holding at, a specific temperature. This is usually followed by a slow cool for the sole purpose of relieving the internal stresses created as a result of spring coiling.
Superalloy An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory and shock) are encountered and where oxidation resistance is frequently required.
Tempering Reheating a quench hardened or normalized ferrous alloy to a temperature below the transformation range and then cooling at any rate desired.
Tensile Strength In tensile testing, the ratio of maximum load to original cross-sectional area. Also called ultimate strength.
Tensile Test A test performed to determine the overall strength of the metal. The test sample is grasped in two opposing grips and pulled apart until it breaks. This test provides information related to a products durability.
Tension Spring A closely coiled spring made to resist a force pulling in the direction of its length. Also called Extension Spring.
Three-Quarter Hard A temper of nonferrous alloys characterized by values of tensile strength and hardness about midway between those of half hard and full hard tempers.
Tolerance The specified permissible deviation from a specified nominal dimension, or the permissible variation in size or other quality characteristic of a part.
Torsion Test A test that involves twisting an object to test a material shear strength.
Torsion Spring A spring that works by torsion or twisting. When it is twisted it exerts a force in the opposite direction proportion to the amount it was twisted.
Vacuum Melting Melting in a vacuum to prevent contamination from air, as well as to remove gasses already dissolved in the metal; the solidification may also be carried out in a vacuum or at low pressure.
Wiredrawing Reducing the cross-section of wire by pulling it through a die.
Yield Strength The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An offset of 0.2% is used for many metals.