E – H
Earing
The formation of scallops (ears) around the top edge of a drawn part caused by differences in the directional properties of the sheet metal used.
Eccentricity
The displacement of the I.D. of the tube with respect to its O.D. Eccentricity results in the variation of wall thickness normal to seamless tubing.
Eddy Current
Non-destructive testing method using eddy current flow for the purpose of recognizing a discontinuity in the piece being tested.
Eddy-Current Testing
Nondestructive testing method in which eddy-curent 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 for subsequent analysis by suitable instrumentation and techniques.
Edge Filing
A method whereby the raw or slit edges of strip metal are passed or drawn one or more times against a series of files, mounted at various angles. This method may be used for deburring only or filing to a specific contour including a completely rounded edge.
Edge Strain or Edge Breaks
Creases extending in from the edge of the temper rolled sheet.
Edges
Many types of edges can be produced in the manufacture of flat rolled metal products. Over the years the following types of edges have become recognized as standard in their respective fields. . Copper Base Alloys- Slit, Slit and Edge Rolled, Sheared, Sawed, Machined or Drawn . Sheet Steels or Aluminum Sheet- Mill Edge, Slit Edge or Sheared Edge. . Strip Steels and Stainless Strip . No. 1 Edge A- Smooth, uniform, round or square edge, either slit or filed or slit and edge rolled as specified, width tolerance +/- .005. . No. 2 Edge- A natural sound mill edge carried through from the hot rolled band. Has not been slit, filed, or edge rolled. Tolerances not closer than hot-rolled strip limits. . No. 3 Edge – Square, produced by slitting only. Not filed. Width tolerances close. . No. 4 Edge – A round edge produced by edge rolling either from a natural mill edge or from slit edge strip. Not as perfect as No. 1 edge. Width tolerances liberal. . No. 5 Edge – An approximately square edge produced by slitting and filing or slitting and rolling to remove burr. . No. 6 Edge – A square edge produced by square edge rolling, generally from square edge hot-rolled occasionally from slit strip. Width tolerances and finish not as exancting as No. 1 edge.
Edging
The dressing of metal strip edges by rolling, filing or drawing.
Elastic Limit
Maximum stress that a material will stand before permanent deformation occurs.
Elastic Limit
The maximum stress to which a material may be subjected without any permanent strain remaining upon complete release of the stress.
Elastic Strain
Dimensional changes accompanying stress where the original dimensions are restored upon release of the stress.
Electocleaning (Electrolytic Brightening)
An anodic treatment. A cleaning, polishing, or oxidizing treatment i which the specimen or work is made the anode in a suitable electrolyte; an inert metal is used as cathode and a potential is applied.
Electrical Conductivity
One of the physical properties of aluminum. It denotes the ability of a particular temper of a particular alloy to carry an electrical current. All published ratings, shown as a percentage, are based on the conductivity of copper which carries a 100% rating, which is the standard. As an example, based on data available, 6061-T6 will have a conductivity rating of 43% when it is compared to a copper product having the same overall dimensions. If however, we are to take density into consideration and compare the 6061-T6 product to a copper product equal to it in weight, the conductivity of the aluminum item would jump to 142%.
Electric Furnace
A clean steel making process wherein the furnace charge of selected scrap is melted using the heat of electricity arcing between electrodes and the furnace charge. The advantage of this furnace is that it permits close control of temperature, heat analysis, and refining conditions.
Electric Furnace Steel
Steel made in any furnace where heat is generated electrically, almost always by arc. Because of relatively high cost, only tool steels and other high-value steels are made by the electric furnace process.
Electric Resistance Welded (ERW)
This is probably the most common method of producing welded tubing. Hot rolled or cold rolled sheet or strip is put through a gradual forming operation until the edges are joined together by the introduction of an electric charge which melts and fuses-or welds-the edges together. ERW is considered a cold forming operation because the steel is formed without heating the sheet or strip. ERW is used for carbon steel products.
Welded Hot Rolled ERW tubing exhibiting the pickled surface of hot rolled strip.
Welded Cold Rolled ERW tubing exhibiting the surface of cold rolled strip.
Drawn Tubing that is unheat-treated, cold drawn tubing and has a scale free cold drawn surface.
Bright Annealed Welded tubing normalized in a controlled atmosphere furnace and which exhibits a bright surface.
Pickled Tubing that has had the scale from hot fabrication or heat treatment removed by one of several types of acid solutions.
Gun Metal Finish Welded tubing normalized, annealed or stress relieved in a controlled atmosphere furnace which exhibits a gun metal finish.
Flash-In Tubing Welded tubing which still retains the I.D. bead or flash formed during the welding operation. It can be furnished in either the as-welded, sunk or heat-treated condition.
Flash-Removed Welded tubing from which the I.D. flash formed during the welding operation has been removed by some mechanical method. It can be furnished in either the as-welded, sunk or heat-treated condition.
Special Smooth I.D. A cold drawn tube in which special attention is paid to the internal surface. Depth of pits and scores in I.D. are guaranteed to be below published maximum depths. Microinch finish is guaranteed in ERW tubes.
Electro-Galvanizing
Galvanizing by Electro deposition of zinc on steel.
Electrolytic Tin Plate
Black Plate that has been Tin plated on both sides with commercially pure tin by electrodeposition.
Electron Beam Microprobe Analyzer
An instrument for selective chemical analysis of a small volume of material. An electron beam bombards the area of interest and x-radiation thereby emitted is analyzed in a spectrometer.
Electroplating
The production of a thin coating of one metal on another by electodeposition. It is very extensively used in industry and is continuing to enlarge its useful functions. Various plated metal and combinations therof are being used for different purposes, to illustrate: 1. Decorative and protection against corrosion…………..copper, nickel and chromium . 2. Protection against corrosion…………………………………cadmium or zinc . 3. Protection against wear……………………………………….chromium . 4. Build-up of a part or parts undersize……………………….chromium or nickel . 5. Pate for rubber adhesion………………………………………brass . 6. Protection against carburization and for brazing operations….copper and nickel
Electropolishing
Improving the specular reflectivity of a metal surface by electrochemical dissolution.
Elongation
In tensile testing, the increase in the gauge length, measured after fracture of the specimen within the gauge length, usually expressed as a percentage of the original gauge length.
Elongation After Fracture
In tensile testing, the increase in the gauge length measured after fracture of the specimen within the gauge length and usually expressed as a percentage of the original gauge length.
Embossing
Raising or indenting a design in relief on a sheet or strip of metal by passing between rolls of desired pattern.
Endurance Limit
Maximum alternating stress which a given material will withstand for an infinite number of times without causing fatigue failure.
Epitaxy
Induced orientation of the lattice of a crystal of a surface deposit by the lattice of the substrate crystal.
Eqilibrium Diagram
A graphical representation of the temperature, pressure and composition limits of phase fields in an alloy system as they exist under conditions of thermodynamical equilibrium. In condensed systems, pressure is usually considered constant.
Equiaxed Structure
A structure in which the grains have approximately the same dimensions in all directions.
Erichsen Test
A cupping test in which a piece of sheet metal, restrained except at the center, is deformed by a cone-shaped spherical-end plunger until fracture occurs. The height of the cup in millimeters at fracture is a measure of the ductility.
Etchant
A chemical solution used to etch a metal to reveal structural details.
Etching
Subjecting the surface of a metal to preferential chemical or electrolytic attack to reveal structural details.
Eutectoid
(1) An isothermal reversible transformation in which a solid solution is converted into two or more intimately mixed solids, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectoid point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectoid transformation.
Exfoliation
A type of corrosion that progresses approximately parallel to the outer surface of the metal, causing layers of the metal to be elevated by the formation of corrosion product.
Expander Steel
Hardened and tempered, blue polished. Carbon content about 1.00, Chromium .17. Used for the expanders in oil piston rings. Hardness 30 N 70 to 73. Range of sizes run for grooves 3/32 to 1/4 wide with the steel approximately .003 less than the grooves and thickness from .012 to .020.
Extensometer
An apparatus for indicating the deformation of metal while it is subjected to stress.
Extensometer Test
The measurement of deformation during stressing in the elastic range, permitting determination of elastic properties such as properties such as proportional limit, proof stress, yield strength by the offset method and so forth. Requires the use of special testing equipment and testing procedures such as the use of an extensometer or the plotting of a stress-strain diagram.
Extra Hard Temper
In brass mill terminology, Extra Hard is six B&S numbers hard or 50.15% reduction from the previous annealing or soft stage.
Extra Spring Temper
In brass mill terminology. Extra Spring is ten numbers hard or 68.55% reduction in thickness from the previous annealing or soft stage.
Extruded Seamless Process
This process involves compressing or forcing material, such as steel or aluminum, through a die into solids (round or special shape) or through a die and over a mandrel to form a tubular shape. Although it may sound complicated, the process is much like squeezing toothpaste out of a tube. Most stainless and aluminum seamless tubing is produced this way.
Extruded Shapes
Continuous lineal shapes produced by forcing a preheated billet into and through an orifice, or opening, in a steel die under great pressure, thus causing the metal to assume the shape of that opening. Oversimplified, it might be likened to squirting icing through various shaped openings with a cake-decorating gun.
Extrusion
Shaping metal into a chosen continuous form by forcing it through a die of appropriate shape.
Face Centered (concerning cubic space lattices)
Having equivalent points at the corners of the unit cell and at the centers of its six faces. A face-centered cubic space lattice is characteristic of one of the slose-packed arrangements of equal hard spheres.
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.
Fatigue Life
The number of cycles of stress that can be sustained prior to failure for a stated test condition.
Fatigue Limit
The maximum stress below which a materiel can presumable endure an infinite number of stress cycles. If the stress is not completely reversed, the value of the mean stress, the minimum stress or the stress ratio should be stated.
Fatigue Strength
The maximum stress that can be sustained for a specified number of cycles without failure, the stress being completely reversed within each cycle unless otherwise stated.
Ferrite
A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams ther are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed.
Ferrite Banding
Parallel bands of free ferrite aligned in the direction of working. Sometimes referred to a ferrite streaks.
Ferrite-pearlite Banding
Inhomogeneous distribution of ferrite and pearlite aligned in filaments or plates parallel to the direction of working.
Ferritic Grain Size
The grain size of the ferric matrix of a steel.
Ferritic Stainless Steel
A term used to identify certain high-chromium content, stainless steels, such as Types 409, 430, 434, 430F, 439, 442 and 446. These steels are essentially non-hardenable by heat treatment and only slightly hardenable by cold work. They are magnetic in all conditions and have good scaling resistance. These steels are called ferritic because in a heat treated condition ferrite is the predominant phase. When viewed under a microscope it looks like a low-carbon iron.
Ferro-Manganese
An alloy of iron and manganese (80% manganese) used in making additions of manganese to steel or cast-iron. Ferroalloy, An alloy of iron with a sufficient amount of some element or elements such as manganese, chromium, or vanadium for use as a means in adding these elements into molten steel.
Ferrous
Related to iron (derived from the Latin ferrum). Ferrous alloys are, therfore, iron base alloys.
Fiber
(1) The characteristic of wrought metal that indicates directional properties. It is revealed by etching a longitudinal section or manifested by the fibrous appearance of a fracture. It is caused chiefly by extension of the constituents of the metal, both metallic and nonmetallic, in the direction of working. (2) The pattern of preferred orientation of metal crystal after a given deformation process.
Fiber or Fibre
Direction in which metals have been caused to flow, as by rolling, with microscopic evidence in the form of fibrous appearance in the direction of flow.
Fiber Stress
Unit stress which exists at any given point in a structural element subjected to load; given as load per unit area.
Fiber Stress
Local stress through a small area (a point or line) on a section where the stress is not uniform, as in a beam under a bending load.
Fibrous Fracture
A fracture whose surface is characterized by a dull gray or silky appearance.
Filed Edges
Finished edges, the final contours of which are produced by drawing the strip over a series of small steel files. This is the usual and accepted method of dressing the edges of annealed spring steel strip after slitting in cases where edgewise slitting cracks are objectionable or slitting burr is to be removed.
Filler Metal
A third material that is melted concurrently with the parent metal during fusion or braze welding. It is usually, but not necessarily, of different composition from the parent metals.
Finery
A charcoal-fueled hearth furnace used in early processes for converting cast iron to wrought iron by melting and oxidizing it in an air blast, then repeatedly oxidizing the product in the presence of a slag. The carbon oxidizes more rapidly than the iron so that a wrought iron of low carbon content is produced.
Finish
A term to describe the surface of any metal and always used in connection with another descriptive word. Examples: Hot finish, cold finish, mill finish, bright finish.
Finished Steel
Steel that is ready for the market without further work or treatment. Blooms, billets, slabs, sheet bars, and wire rods are termed semi-finished produced by the in-the-line thermal treatment following electrodeposition.
Finishing
A broad classification denoting production operations performed on a material to alter its appearance, to improve its corrosion resistance, to enhance its aesthetics or to prepare it for some special application.
MECHANICAL FINISHING includes buffing, polishing, grinding, sanding or even subjecting a surface to sand or shot blasting.
CHEMICAL FINISHING includes preparation for painting or anodizing with conversion coating. Caustic etching and bright dipping are examples.
ELECTROLYTIC FINISHING covers any of the various anodizing processes.
APPLIED FINISHING involves painting, laminating, plating or porcelainizing.
Finishing Temperature
The temperature at which hot working is completed.
Finish Machine Size
Normally specified in terms of the maximum-machined O.D. and the minimum machined I.D. as applied to tubular parts. Finish machine size represents the size of the part as it comes from the final machining operation. From this size the tube mill can calculate a tube size which will be guaranteed to cleanup upon machining.
Fish eyes
Areas on a fractured steel surface having a characteristic white crystalline appearance.
Flakes
Short discontinuous internal fissures in ferrous metals attributed to stresses produced by lacalized transformation and decreased solubility of hydrogen during cooling after hot working. In a fractured surface, flakes appear as bright silvery areas; on an etched surface thay appear as short discontinuous cracks. Also called shatter cracks and snowflakes.
Flame Annealing
Annealing in which the heat is applied directly by a flame.
Flame Annealing
A process of softening a metal by the application of heat from a high-temperature flame.
Flame Cutting
A process used in most service centers to cut plate products to the customers desired size and/or shape.
Flame Hardening
A process of hardening a ferrous alloy by heating it above the transformation range by means of a high-temperature flame, and then cooling as required.
Flapper Valve Steel
An extremely flat, very smooth, very accurate to gage, polished, hardened and tempered spring steel produced from approximately 1.15 carbon. The name is derived from its common and principle usage.
Flare Test
A test applied to tubing, involving a tapered expansion over a cone. Similar to pin expansion test.
Flash
(1) In forging, the excess metal forced between the upper and lower dies. (2) In resistance butt welding, a fin formed perpendicular to the direction of applied pressure.
Flash Condition
When the edges of the tubing are brought to fusion temperature, side roll exert sufficient pressure to press the heated edges together, forming a welded joint. A small amount of metal is extruded on the O.D. and I.D. of the tube. No foreign or additional metal is added in this operation. The extruded metal on the outside is always removed to form a smooth outside surface.
Flash Controlled .005 and .010
This means that the inside flash is controlled to the maximum limits shown. This is usually required where the customer telescopes one size into another, uses a mandrel in fabrication or is inserting something inside the tube.
Flash-In Tubing
Tubing with the welding flash left on the inside of the tubing.
Flash Welding
A resistance butt welding process in which the weld is produced over the entire abutting surface by pressure and heat, the heat being produced by electric arcs between the members being welded.
Flat Latch Needle Steel
Supplied cold rolled and annealed. Carbon content .85. Supplied both in coil and flat length. Used to make flat latch needles which are used in the manufacture of knitted goods.
Flat Wire
A flat Cold Rolled, prepared edge section up to 1 1/4 wide, rectangular in shape. Generally produced from hot rolled rods or specially prepared round wire by one or more cold rolling operations, primarily for the purpose of obtaining the size and section desired. May also be produced by slitting cold rolled flat metal to desired with followed by edge dressing.
Flatness
Flatness refers to the deviation from a flat plane and is described in terms of the amount of deviation from that plane and the shape of the deviation. For example, the corrugated siding with which we are all familiar might be described as having 1-1/2 waves on a 4-inch center.
Floating Plug
A plug that locates itself inside a tube during drawing, in such a way that the tube is reduced in thickness between the plug and the die.
Flow Lines
(1) Texture showing the direction of metal flow during hot or cold working. Flow lines often can be revealed by etching the surface or a section of a metal part. (2) In mechanical metallurgy, paths followed by volume elements of metal during deformation.
Flow Stress
The shear stress required to cause plastic deformation of solid metals.
Flowlines
Always visible to a greater or less degree when a longitudinal section has been subjected to Macro etching, indicating the direction of working or rolling.
Fluting
Kinking or breakage due to curving of metal strip on a radius so small, with relation to thickness, as to stretch the outer surface above its elastic limit. Not to be confused with the specific product, Fluted Tubes.
Flux
(1) In refining, a material used to remove undesirable substances as a molten mixture. It may also be used as a protective covering for molten metal. (2) In welding, a material used to prevent the formation of, or to dissolve and facilitate the removal of, oxides and other undesirable substances.
F.O.B.
This shipping term is an abbreviation for Free on Board. It means that as the shipment is loaded on the carrier, ownership is transferred from the mill to the customer.
Foil
Metal in sheet form less than 0.006 in. in thickness.
Foil
Metal in any width but no more than about 0.005 thick.
Folds
Defects caused in metal by continued fabrication of overlapping surfaces.
Forge Welding
Welding hot metal by applying pressure or blows.
Forging
Plastically deforming metal, usually hot, into desired shapes with compressive force, with or without dies.
Forging Stock
A mill produced rod, bar or special shaped piece of metal that is suitable after heating for forging. Forging stock is usually supplied in the F temper because it will be annealed as it is heated for forging.
Fractography
Descriptive treatment of fracture, especially in metal, with specific reference to photography of the fracture surface.
Fracture
Surface appearance of metals when broken.
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, soundness, and presence of defects.
Fragmentation
The subdivision of a grain into small discrete crystallites outlined by a heavily deformed network of intersecting slip bands as a result of cold working. These small crystals or fragments differ from one another in orientation and tend to rotate to a stable orientation detemined by the slip systems.
Free Machining
Pertains to the machining characteristics of an alloy to which one or more ingredients have been introduced to produce small broken chips, low power consumption, better surface finish or longer tool life.
Fretting (Fretting Corrosion)
Action that results in surface damage, especially in a corrosive environment, when there is relative motion between solid surfaces in contact under pressure.
Friction Gouges or Scratches
A series of relatively short surface scratches variable in form and severity. Refer to Galling.
Full Annealing
Annealing a ferrous alloy by austenitizing and then cooling slowly through the transformation range. The austenitizing temperature to hypoeutectoid steel is usually above Ac3; and for hypereutectoid steel, usually between Ac1 and Ac (cm).
Full Finish Plate
Steel sheet or strip, reduced either hot or cold, cleaned, annealed, and then cold-rolled to a bright finish.
Full Hard Temper
(A) (No. 1 Temper) In low carbon sheet or strip steel, stiff and springy, not suitable for bending in any direction. It is the hardest temper obtainable by hard cold rolling. (B) In Stainless Steel Strip, tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Full Hard temper is 185,000 TS, 140,000 YS Min. Term also used in connection with copper base alloys and considered synonymous with Hard Temper.
Fusion Welding
Any welding process in which fusion is employed to complete the weld.
Gages
Mfrs. standard numbering systems indicating decimal thickness’ or diameters.
Galling
The damaging of one or both metallic surfaces by removal of particles from localized areas due to seizure during sliding friction.
Galvanic Corrosion
Corrosion associated with the current of a galvanic cell consisting of two dissimilar conductors in an electrolyte or two similar conductors in dissimilar electrolytes. Where the two dissimilar metals are in contact, the resulting action is referred to as couple action.
Galvanizing
Coating steel with zinc and tin (principally zinc) for rust proofing purposes. Formerly for the purpose of galvanizing, cut length steel sheets were passed singly through a bath of the molten metal. Today’s galvanizing processing method consists of uncoiling and passing the continuous length of successive coils either through a molten bath of the metal termed Hot Dipped Galvanizing or by continuously zinc coating the uncoiled sheet electrolytically- termed Electro-Galvanizing.
Gamma Iron
The form of iron stable between 1670 (degrees) F., and 2550 (degrees) F., and characterized by a face-centered cubic crystal structure.
Gas Welding
Welding with a gas flame.
Gear
There are many different types of gears, and they are all basically used in a mechanism to determine mechanical advantage, reduce or increase speed, or determine direction of travel.
GFM – Gyratory Forging Machine
A machine designed to hot forge a cylindrical bar shape while it is turning at speed.
Gilding Metal
A copper-zinc alloy containing 95% copper and 5% zinc. While similar to deoxidized copper in physical properties, it is somewhat stronger and very ductile. It has thermal and electrical conductivity slightly better than half that of electrolytic copper and corrosion resistance comparable to copper.
Grain
An individual crystal in a polycrystalline metal or alloy, including twinned regions or subgrains if present.
Grain Boundary
Bounding surface between crystals. When alloys yield new phases (as in cooling), grain boundaries are the preferred location for the appearance of the new phase. Certain deterioration, such as season cracking and caustic embrittlement, occur almost exclusively at grain boundaries.
Grain Coarsening
A heat treatment that produces excessively large austenitic grains.
Grain Flow
Fiber like lines appearing on polished and etched sections of forgings, caused by orientation of the constituents of the metal in the direction of working during forging.
Grain Growth
An increase in the average size of the grains in polycrystalline metal or alloy, usually a result of heating at elevated temperature.
Grain Growth
An increase in metallic crystal size as annealing temperature is raised; growth occurs by invasion of crystal areas by other crystals.
Grain Size
(1) For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. Grain sizes are reported in terms of grains per unit area or volume, average diameter, or as a grain-size number derived form area measurements.
Grain-Boundary Liquidation
An advanced stage of overheating in which material in the region of austenitic grain boundaries melts. Also known as burning.
Grain-Boundary Sulfide Precipitation
An intermediate stage of overheating in which sulfide inclusions are redistributed to the austenitic grain boundaries by partial solution at the overheating temperature and reprecipitation during subsequent cooling.
Grains
Individual crystals in metals.
Granular Fracture
A type of irregular surface produced when metal fractures, characterized by a rough, grain like appearance as differentiated from a smooth silky, or fibrous, type. It can be sub classified into trans-granular and inter-granular forms.. This type of fracture is frequently called crystalline fracture, but the implication that the metal has crystallized is completely misleading.
Granulated
A coarse grain or pebbly surface condition which becomes evident during drawing.
Granulation
The formation of grains immediately upon solidification.
Graphite
The polymorph of carbon with a hexagonal crystal structure.
Graphitizing
A heating and cooling process by which the combined carbon in cast iron or steel is transformed, wholly or partly, to graphitic or free carbon.
Gray Cast Iron
A cast iron that gives a gray fracture due to the presence of flake graphite. Often called gray iron.
Grinding
Removing material from from a work piece with a grinding wheel or abrasive belt.
Grinding Cracks
Shallow cracks formed in the surface of relatively hard materials because of excessive grinding heat or the high sensitivity of the material.
Grit
Grit refers to small particles of something that tend to be abrasive. The coarseness or fineness of grit is defined by a numbering system, with coarse grit having low numbers such as 12 and fine grit having high numbers such as 1000. It also relates to the shot that is used to blast the rolls for the skin pass mills that create different mane finishes.
Ground Flat Stock
Annealed and pre-ground (to close tolerances) tool steel flats in standard sizes ready for tool room use. These are three common grades; water hardening, oil hardening, and air hardening quality.
Guide
Device for holding the metal in the proper position, during rolling, or slitting.
Guide Scratch
Scratches or marks appearing parallel to edges of cold rolled strip caused by scale or other particles which have become imbedded in or have adhered to the rolling mill guide. Also applies to similar scatches appearing as a result of slitting.
Gun Drill
A drill, usually with one or more flutes and with coolant passages through the drill body, used for deep hole drilling.
Half Hard Temper
(A) In low carbon cold-rolled strip steel, produced by cold rolling to a hardness next to but somewhat softer than full hard temper. (B) In brass mill terminology, half hard is two B&S numbers hard or 20.70% thickness reduction. (C) In Stainless Steel Strip, Tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Half-Hard Temper 150,000 T.S., 110,000 Y.S.Min.
Hammer Forging
Forging in which the work is deformed by repeated blows. Compare with press forging.
Hard Chromium
Chromium deposited for engineering purposes, such as increasing the wear resistance of sliding metal surfaces, rather than as a decorative coating. It is usually applied directly to basis metal and is customarily thicker than a decorative deposit.
Hard Alloys
A term used to denote the higher strength alloys. (See heat-treatable alloys)
Hard Drawing
Drawing metal wire through a die to reduce cross section and increase tensile strength.
Hard Drawn
Wire or tubing drawn to high tensile strength by a high degree of cold work.
Hard Drawn Spring Steel Wire
A medium high carbon cold drawn spring steel wire. Used principally for cold wound springs.
Hard Temper
(A) (For steel see Full Hard Temper) (B) In brass mill terminology. Hard Temper is four B&S numbers hard or 37.1% reduction.
Hardenability
In a ferrous alloy, the property that determines the depth and distribution of hardness induced by quenching.
Hardenability
In ferrous alloys, the property that determines the depth and distribution of hardness induced by quenching.
Hardened and Tempered Spring Steel Strip
A medium or high carbon quality steel strip which has been subjected to the sequence of heating, quenching and tempering.
Hardening
Any process which increases the hardness of a metal. Usually heating and quenching certain iron base alloys from a temperature either within or above the critical temperature range.
Hardness
Degree to which a metal will resist cutting, abrasion, penetration, bending and stetching. The indicated hardness of metals will differ somewhat with the specific apparatus and technique of measuring. For details concerning the various types of apparatus used in measuring hardness, See Brinell Hardness, Rockwell Hardness, Vickers Hardness, Scleroscope Hardness. Tensile Strength also is an indication of hardness.
Hardness (indentation)
Resistance of a metal to plastic deformation by indentation. Various hardness tests such as Brinell, Rockwell and Vickers may be used. In the Vickers test, a diamond pyramid with an included face angle of 136 is used as the indenter.
Heat
The quantity of steel produced by a furnace with one melting. Steel melting is a batch process and each batch is a heat.
Heat of Steel
The product of a single melting operation in a furnace, starting with the charging of raw materials and ending with the tapping of molten metal and consequently identical in its characteristics.
Heat Number
An identifying number assigned to the product of one melting in an electric arc furnace: e.g. 19345. Sometimes but not universally, the first digit indicates the furnace number: the second digit indicates the year in which the heat was melted. The last three digits show that this was the 345th heat melted in No. 1 furnace during 1989.
Heat Resistance Steel
Steel whose composition and treatment specifically prepare it for service at elevated temperatures. The term is less restrictive than oxidation resistant that refers to resistance to gaseous corrosion at high temperatures.
Heat Tinting
Colouration of a metal surface through oxidation by heating to reveal details of structure.
Heat Treatment
Heating and cooling a solid metal or alloy in such a way that desired structures, conditions or properties are attained. Heating for the sole purpose of hot working is excluded from the meaning of this term.
Heat-Affected Zone
That portion of the base metal which was not melted during brazing, cutting or welding, but within which microstructure and physical properties were altered by the treatment.
Hematite
The oxide of iron of highest valency which has a composition close to the stoichiometric composition Fe2O3.
High Brass
65% A copper-zinc alloy containing 35% zinc. Possesses high tensile strength. Used for springs, screws, rivets, etc.
High Strength Steel
Commonly known as High Strength-Low Alloy (HSLA) A specific class of low alloy steels in which increased mechanical properties and, usually, good resistance to atmospheric corrosion is obtained with moderate amounts of one or more alloying elements other than carbon. Galvanized flat steel sheets (HSLA) are coated with zinc by the continuous hot-dip process. You can also achieve high strength through physical, not chemical, properties.
Hollow Shape
An extruded shape whose cross-section completely encloses a void.
Homogenizing
Holding at high temperature to eliminate or decrease chemical segregation by diffusion.
Homogenizing Annealing
An annealing treatment carried out at a high temperature, approaching the solidus temperature, for a sufficiently long time that inhomogeneous distributions of alloying elements are reduced by diffusional processes.
Honing
Removing stock generally on the internal cylindrical surface of a workpiece with an abrasive stick mounted in a holder.
Hooke’s Law
Stress is proportional to strain in the elastic range. The value of the stress at which a material ceases to obey Hooke’s law is known as the elastic limit.
Hot Dip
In steel mill practice, a process wherby ferrous alloy base metals are dipped into molten metal, usually zinc, tin, or terne, for the purpose of fizing a rust resistant coating.
Hot Finished
(Hot Fin)
Nickel alloys are referred to as hot finished when they have been rolled to size at elevated temperature and have undergone no further reduction.
Hot Finish Seamless Process
In this process, a solid shape, generally a heated special quality bar sometimes called a tube round or billet, is pierced with a solid mandrel to form a tube hollow or shell. This tube hollow is further worked to produce a hot finished seamless tube. Carbon and alloy tubing is produced this way.
Hot Finished Seamless Tubing
Tubing produced by rotary piercing, extrusion and other hot working processes without subsequent cold finishing operations.
Hot Rolled
Hot rolled products are those that are rolled to finish at temperatures above the recrystallization temperature.
Hot Rolled ERW Tubing
As welded electric resistance welded tubing made from hot rolled strip or sheet.
Hot Short
Brittleness in hot metal.
Hot Shortness
Brittleness in metal in the hot forming range.
Hot Strength Reduced
A process that is utilized to obtain tubing in smaller diameter sections. Material is heated, and while hot, stretched and reduced in diameter to achieve desired wall.
Hot Top
(1) A reservoir, thermally insulated or heated, to hold molten metal on top of a mold to feed the ingot or casting as it contracts on solidifying to avoid having pipe or voids.
Hot Working
Plastic deformation of metal at a temperature sufficiently high not to create strain hardening. The lower limit of temperature for this process is the recrystallization temperature.
Hydraulic Cylinder Tubing
This tubing is, as the name implies, used to produce hydraulic cylinders. It is available in two grades, regular DOM and Special Smooth I.D. (SSID) DOM is not furnished with an I.D. of cylinder quality. The I.D. is sometimes surface finished by the steel service center. SSID tubing is an excellent choice for certain types of hydraulic cylinders where no further finishing of the I.D. is desired or required.
Hydraulic Fluid Line Tubing
Probably the highest quality carbon or alloy tubing made. Its name tells you the applications for which it is used. They require special conditions of the tubing; special surface finishing, flarability, certain Rockwell hardness, restrictive elongation, and in many cases, special pressure testing procedures.
Hydrogen Embrittlement
A condition low ductility in metals resulting from the absorbtion of hydrogen.
Hydrostatic Test
A test in which a liquid, usually water, under pressure, is used internally to detect and locate leaks in a tube of a fabricated structure.
Hypereutectoid Steel
A steel having more than the eutectoid percentage of carbon.