Ra - Chemical symbol for Radium

R Enamel - An unpigmented enamel used to increase resistance to corrosion, or decrease bleaching effect of tinplate on food can interiors.

R1-Valves - Double-gated valves that allow particulate to drop out of the vacuum gas stream with minimal air loss.

Rack - An array of gears spaced on a straight bar.

Radial - In a direction directly outward from the center of a circle or sphere or from the axis of a cylinder. The spokes of a wheel, for example, are radial.

Radial Ring Rolling Mill (RW) - A type of ring forging equipment for producing seamless rolled rings by controlling only the outside and inside diameters.

Radial Roll - (main roll, king roll)

Radial Rolling Force - The action produced by the horizontal pressing force of the rolling mandrel acting against the ring and the main roll. Usually expressed in metric tons.

Radiant Heat - Heat communicated by radiation and transmitted by electromagnetic waves.

Radiant Tube Annealing Box - A box which is heated, inside, by means of tubes in which gas is burned; the hot tubes radiate their heat to the covered pile of metal, standing on the base of the box. Usually a protective atmosphere is maintained in the box to protect the metal from oxidation.

Radiation Area - Any part of an installation accessible to employees in which there exists a radiation level of 7.5 millirem in any one hour over 150 millirem in any seven consecutive days.

Radiation Hazard - Any situation where persons might be exposed to radiation in excess of the maximum permissible dose.

Radiation, Direct - All radiation coming from within an x-ray tube and tube housing except the useful beam.

Radioactive Isotopes - Varieties of an element possessing the same chemical characteristics but emitting detectable radiation's by means of which they can be identified and traced.

Radioactive Material - Any compound or element which may emit any or all of the following: alpha and beta particles, electrons, photons neutrons and gamma and all other emissions which produce ionization directly or indirectly.

Radiography - A nondestructive method of internal examination in which metal objects are exposed to a beam of X-ray or gamma radiation. Differences in thickness, density or absorption, caused by internal defects or inclusions, are apparent in the shadow image either on a fluorescent screen or on photographic film placed behind the object.

Radium - A radioactive element which the chemical symbol Ra; radium and its salts are used in gamma-ray radiography because of their radioactivity. Melting point is 700 B0C (1292 B0F).

Radius - The distance from the center of a circle to its circimference (outside).

Reactive Power (See VARS below) The part of the electricity used by a motor or transformer (or similar device) that is used to magnetize the iron. (You have to magnetize the iron to create the magnetic field that makes the device work.) -

Rake - That surface of a cutting tool against which the chips bear while beign severed. If this surface is less than 90 from the surface being cut, the rake is positive. If more, the rake is negative.

Ram - The moving or falling part of a drop hammer or press to which one of the dies is attached; sometimes applied to the upper flat die of a steam hammer.

Ramming - Packing sand in a mold by raising and dropping the sand, pattern, flask on a table. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle.

Range - The difference between the highest and lowest values of a measurable attribute of the output of a process.

Rapid Traverse - A lever-controlled, power-operated feature of some machines that permits the rapid movement of the worktable from one position to another.

Rapping - Knocking or jarring the pattern to loosen it from the sand in the mold before withdrawing the pattern.

Rare Earth (RE) - Any of a group of 15 similar metals with atomic numbers 57 to 71. Also rare earth element, rare earth metal, lanthanide series, uncommon metals, Mischmetal.

Rare Gases - Helium, argon, neon, krypton, xenon and radon.

Rat Tail - An expansion discontinuity in a sand casting, featured as a long, narrow, linear depression, resulting from sand expansion and minor buckling of the mold surface during filling of the mold.

Raw Water - Untreated river water.

Rb - Chemical symbol for Rubidium

RCS - Abbreviation for Rigid Container Sheet

Re-pickle - Coil that will be reprocessed. Also Reclean, Reroll, and Reanneal.

Re - Chemical symbol for Rhenium

Reactive Power (See VARS below) The part of the electricity used by a motor or transformer (or similar device) that is used to magnetize the iron. (You have to magnetize the iron to create the magnetic field that makes the device work.) - NULL

Reactor - A large inductor. Inductors have the characteristics of limiting electrical power surges that would occur when a large amount of current attempts to flow very quickly. In the WSX system, we use reactors to limit these surges between the power house #2, #3, and #4 buses.

Readings - Readings taken from instruments and written on log sheet.

Reaming, line - The process of reaming two or more holes to bring them into very accurate alignment.

Rear End Condition - See Back End Condition.

Recalescence - An increase of temperature that occurs while cooling metal through a range of temperatures in which changes in metal occur.

Recarburizing - (1) Increasing the carbon content of molten cast iron or steel by adding carbonaceous material, high-carbon pig iron or a high-carbon alloy. (2) Carburizing a metal part to return surface carbon lost in processing.

Receiving Ladle - A ladle placed in front of the cupola into which all metal is tapped. It acts as a mixer and reservoir and to smooth out metal flow to the pouring area.

Recess - An internal groove.

Recirculating Line - Line that relieves the pressure between the feedwater pump and the dearator tank.

Recirculating Water - Keeps water from dead heading in feed water pumps.

Recovery Pump - A pump that carries water from the gland evacuation pump to the condensate tank for #9 Generator.

Red Brass - 85% Copper -- A copper-zinc alloy containing approximately 15% zinc, used for plumbing pipe, hardware, condenser tubes. Because of its color, is used or vanity cases, coins, plaques, badges, etc. It is somewhat stronger than commercial bronze and is hardened more rapidly by cold working.

Red Hardness - A term sometimes associated with high speed steel because it has the property of retaining sufficient hardness for cutting metals even when heared to atemperature high enough to cause a dull redness. The tungsten content has a significant influence on this property.

Red Rust - A reddish brittle coating of iron oxide which develops on an uncoated or coated steel surface when oxygen in the atmosphere mixes with iron.

Redraw Rod - This term is not recommended. The term Drawing Stock is preferred.

Reducing Agent - Either natural gas or coal can be used to remove the oxygen from iron ore in order to produce a scrap substitute. In gas-based processes, the iron ore is heated in a vessel as reformed natural gas passes through. In coal-based processes, iron ore is combined with gasified or ground coal and heated. The oxygen in the ore combines with carbon and hydrogen in the gas or coal, producing reduced, or metallic, iron.

Reducing Station - Manifolds on both the A.G.C. system and the C.V.C. system that break down the pressure coming from the main pumps into the pressures that the system requires. In the A.G.C. system the reducing station splits the pump pressure into P1, P2 and P3 pressures. In the C.V.C. system, the reducing station splits the pump pressure into P1, P2, P3 andP4 pressures.

Reduction - The removal of oxygen or addition of hydrogen.

Reduction of Area (contraction ofarea) - The difference in a tension specimen, between the size of the original sectional area and that of the area at the point of rupture. It is generally stated as the percentage of decrease of cross sectional area of a tension specimen after rupture.

Reel Breaks - Fractured base metal normally caused by poor leveling. It is indicated by light kinks across the width of the winding coil.

Reel Digs - Especially on high carbon steel, marks made by the Hot Mill reels. These occur because the reels run faster than steel is coming off the line, it actually puts "digs" in itself.

Reel Kinks - Damage on the strip in the core of a coil.

Refined Aluminum - Aluminum of very high purity (99.950 percent or higher) obtained by special metallurgical treatments.

Refining - (a) the removal of impurities and metallic oxides from the molten bath by the reaction of the slag and other additions. (b) A heat treatment process with the object of refining or making the grain size of the steel uniform.

Reflector Sheet - An alclad product containing on one side a surface layer of high-purity aluminum superimposed on a core or base alloy of commercial-purity aluminum or an aluminum-manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability.

Reflectoscope - An instrument for the ultrasonic testing of metals.

Reflow - An area on the plating line where tin on the strip surface is melted and resolidified to get a brite, shiny appearance.

Reflow Plate (Brite) - Process on Tin Platers; section of Tin plater that heats coil and melts the Tin coating.

Reflowed Surface - A shiny tin plate product surface which is achieved by heating the tin coating up to its melting point (thereby melting the tin) and cooling it back to room temperature.

Refractory - A ceramic material that can resist great heat and is therefore suitable for lining furnaces. Fireclay, dolomite, magnesite and silica are examples. This is not to be confused with refractory metals, such as columbium and tantalum.

Refractory Brick - Heat-resistant brick. Because its melting point is well above the operating temperatures of the process, refractory bricks line most steelmaking vessels that come in contact with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF.

Refractory Clay - A clay which fuses at pce 25 (1590C, 2894F) or higher.

Refractory Metal - A metal having an extremely high melting point. In the broad sense, it refers to metals having melting points above the range of iron, cobalt, and nickel.

Regenerator - (Regeneration System) A device used to increase the volume of hydraulic oil going to the work roll change extractor.

Regression Analysis - A statistical method of determining, or predicting, the value of a dependent variable, based on levels of one or more know independent variables.

Reheating - Heating metal again to hot-working temperature. In general no structural changes are intended.

Reinforcing Bar (Rebar) - A commodity-grade steel used to strengthen concrete in highway and building construction.

Rejects Box - Also known as a HOLES box, where scrap sheets accumulate during production.

Release Agent (Parting Agent) - A material, e.g. silicone, stearate, oil, or wax for lubricating a die pattern or core box to facilitate easy removal of a casting, mold or core.

Relief - A term for clearance or clearance angle.

Relief Valve - A valve that is set at a predetermined pressure and will open if a system or component of a system exceeds that set pressure.

Reline - The process of replacing the refractory lining of a liquid steel vessel. Once it wears out, the brick lining of a furnace must be cooled, stripped and replaced. This maintenance can be significant because a blast furnace reline may require up to three months to complete.

Remanence - The remaining flux density after the magnetizing force has been removed.

Remote - A station near a pump consisting of both an 'On' and an 'Off' button. A pump can be started or stopped by its corresponding remote.

Removable Sections - Side panel section of tubes that make up the vessel cover. The removable sections are located on the north and south sides of both boilers.

Reoil - Oil put on the sheet after cleaning and before coiling for shipment to prevent water stain.

Repair Welding - Any welding carried out after delivery to the end user, i.e., after the casting has been in service.

Rephosphorizing (Steel) - A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility. . NOTE: Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.

Replate - To reprocess a coil on the plater that has been plated previously.

Replicast Process (CS) - A ceramic shell process similar to the investment casting process. Uses a pattern made from expanded polystyrene (EPS) and is surrounded by a thin ceramic shell.

Reroll Stock - A semi-finished rolled product of rectangular cross section in coiled form suitable for further rolling. Examples: Foil Stock and Sheet Stock.

Reset - A control button used to energize the side trimmer and welder.

Residual - Any element remaining in any alloy following melting and casting which was not added to meet an analytical specification limit.

Residual Stress - See Stress, Residual

Residual Stress - Macroscopic stresses that are set up within a metal as the result of non-uniform plastic deformation. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.

Residuals - The impurities in mini-mill steel as the result of the mix of metals entering the process dissolved in obsolete scrap. Residuals are key concerns regarding the mini-mills' recent entry into the flat-rolled market, where high residuals can leave sheet steel too brittle for customer use.

Resistance Welding - A type of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion welding. Flash and butt welding are sometimes considered as resistance welding processes.

Resolved Shear Stress - Stress operating on a crystallographic slip system.

Respirator - A filtering device which covers the nose and mouth and prevents inhalation of dust or fumes; should have the U.S. Bureau of Mines certificate or approval for the specific contaminant being filtered out. Handkerchiefs and gauze masks give little or no protection.

Resulfurized Steel - Steel to which sulfur has been added in controlled amounts after refining. The sulfur is added to improve machinability.

Return Filter - A filter that cleans the hydraulic oil of an operating hydraulic system before it returns to the system's storage tank.

Reusable Filter - Type of filter element that can be cleaned in solvent and used again.

Reversing Block - Part of a grease system that changes the flow of grease from one direction to the other after a predetermined pressure has been met.

Reversing Mill - Any rolling mill in which the direction of rotation of the rolls can be reversed at will. Heavy primary mills for bloom and slab rolling are the most common, but others, including some cold-rolling mills, are also made to reverse.

Revert - Recycled sprues, gates, risers, defective castings and machine chips.

Rewind - A coil that needs to be reprocessed on a side trimmer.

Rework - Coil that will be reprocessed. Also Reclean, Reroll, and Reanneal.

Reynolds Numbers - Used in hydraulics and in casting gating theory. A dimensionless value (dynamic viscosity / density) describing the fairly sudden shift of flow from laminar to turbulent. Re > 2000 represents turbulent flow. Laminar flow is seldom experienced in runner and gating systems.

RF Backbone - Hardware and Software which enables real time tracking of inventory by receiving the signal from the scanners and transmitting it to the DEC computer. It includes the scanners, relay base stations, links to the computer and all required software to operate the system.

Rh - Chemical symbol for Rhodium

Rhodium - Chemical symbol Rh. A silver-white metal found in nickel deposits.

Rib - An elongated projection on a shape, forging or casting to provide stiffening.

Ribbing A coating - A coating defect consisting of a flow mark defect with an appearance similar to corduroy fabric. Ribbing usually occurs when the flow marks (ribs), from application on the coater, do not flow out and level the surface of the coating.

Ridge - A hump across the width of the surface of the coil.

Rigging - Gates, risers, loose pieces, etc., needed on the pattern to produce a sound casting.

Rigidity - The degree of flexibility of steel.

Rimmed Steel - Low-carbon steel in which incomplete deoxidation permits the metal to remain liquid at the top of the ingot, resulting in the formation of a bottom and side rim of considerable thickness. The rim is of somewhat purer composition than the original metal poured. If the rimming action is stopped shortly after pouring of the ingot is completed, the metal is known as capped steel. Most steels below 0.15% carbon are rimmed steels. For the same carbon and manganese content rimmed steel is softer than killed steel.

Ring Rolling - The process of shaping weldless rings from pierced disks or thick walled, ring-shaped blanks between rolls that control wall thickness, ring diameter, height, and contour.

Rip - Defect indicating the edge of the strip has been torn and yet is still attached to the strip.

Riser - Reservoir of molten metal from which casting feeds as it shrinks during solidification.

Riser Distance - The length of the riser neck. The term is applied to side risers only.

Riser Height - The distance from the top of the riser when liquid to the top of the riser neck. Riser height when sold is usually several inches less than when liquid because of contraction and loss of feed metal to the casting.

Riser Neck - The connecting passage between the riser and casting. Usually only the height and width or diameter of the riser neck are reported, although the shape can be equally important.

Riser Pad (Riser Contact) - An enlargement of the riser neck where it joins the casting. The purpose of the pad is to prevent the riser from breaking into the casting when it is struck or cut from the casting.

Riser, Blind - A riser that does not break through the top of the cope and is entirely surrounded by sand; opened to the atmosphere by means of a firecracker core.

Riser, Open - Conventional form of riser usually located at the heaviest section of the casting and extending through the entire height of the cope.

Riser, Side (Side Head) - A riser attached to the side of a casting.

Riser, Top (Top Head) - A riser attached to the top surface of a casting.

Riser-Gating - Practice of running metal for the casting through the riser to help directional solidification.

Rock Candy Fracture - A fracture that exhibits separated-grain facets, most often used to describe intergranular fractures in large grained metals.

Rockwell - (Hardness Tester) A device used to determine the hardness of the steel strip. "Rockwell" machines are used to measure hardness of all WSC's products.

Rockwell Hardness - Measure of resistance to penetration when material is exposed to a pointed load. The hardness numbers obtained by a Rockwell machine are related to the depth of the impression measured after the load is applied. See hardness

Rockwell Hardness (Test) - A standard method for measuring the hardness of metels. The hardness is expressed as a number related to the depth of residual penetration of a steel ball or diamond cone (brale) after a minor load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator. Various dial readings combined with different major loads, five scales designated by letters varying from A to H; the B and C scales are most commonly in use.

Rockwell Hardness Testing - A method of determining the relative hardness value of material by measuring the depth of residual penetration by a steel ball or diamond point under controlled loading

Rod, Alclad - Rod having on its surface a metallurgically bonded or aluminum alloy caoting that is anodic to the core alloy to which it is bonded, thus electrolytically protecting the core alloy against corrosion.

Rod, Cold-Finished Extruded - Rod produced by cold working extruded rod.

Rod, Cold-Finished Rolled - Rod produced by cold working rolled rod.

Rod, Cold-Finished - Rod brought to final dimensions by cold working to obtain improved surface finish and dimensional tolerances

Rod, Cold-Heading - Rod of quality suitable for use in the manufacture of cold-headed products such as rivets and bolts

Rod, Extruded - Rod produced by hot extruding.

Rod, Rivet - See Rod, Cold Heading.

Rod, Rolled - Rod produced by hot rolling

Rod - Round, thin semi-finished steel length that is rolled from a billet and coiled for further processing. Rod is commonly drawn into wire products or used to make bolts and nails. Rod trains (rolling facilities) can run as fast as 20,000 feet per minute D1more than 200 miles an hour.

Rod Mill - (1) A mill for fine grinding, somewhat similar to the ball mill, but employing long steel rods instead of balls as the grinding medium. (2) A mill for rolling metal rod.

Rod Side Pressure - Pressure applied to the back side of the head of a cylinder ram or shaft that supplies less force than the blank side pressure.

Rodding - Reinforcing the sand in a core with metal rods or shapes to strengthen parts of the core.

Roll-In Metal - An extraneous chip or particle of metal rolled into the surface of the product.

Roll Forming - An operation used in forming sheet

Roll Grind - The uniform ground finish on the work rolls which is imparted to the sheet or plate.

Roll Force Systems - "Mill stands place considerable pressure on slabs, blooms and coils to further process the material. There are two general ways of applying the force to the steel D1screw and hydraulic systems. SCREW (INCLINE PLANE) This older method used the basic principle of the screw to adjust the space between the mill rolls. Because metal touches metal, these configurations will wear down over time and can cause quality problems. HYDRAULIC (PANCAKE CYLINDER) This modern system uses fluid pressure to rapidly adjust the roll spacing several times per second. These minute, instantaneous adjustments allow for superior gauge tracking and higher-quality products. "

Roll Forming - An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called molded sections.

Roll Forming - 1) An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called "molded sections." 2) A process of coiling sheet into open cylinders.

Roll Scale - Oxide of iron which forms on the surface of steel while it is being heated and rolled. Much of the scale is cracked and loosened during the rolling operation and may fall off the piece naturally or be blown off by high-pressure water sprays or other means.

Rolled Edges - Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edges.

Rolled Ring - See Forging, Rolled ring.

Rolled Edges - Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.

Roller Flattening - The process in which a series of staggered rolls of small diameter is used to remove bow and waves

Roller Level - appreciable reduction in gauge.

Roller Leveling - Passing sheet or strip metal through a series of staggered small rolls so as to flatten the metal. This method is relatively ineffective in removing defects such as buckles, wavy edges, corrugations, twists, etc., or from steel in the higher hardness ranges.

Rolling Ingot - A cast form suitable for rolling. See Fabricating Ingot.

Rolling lap - A fault arising from the overfilling or mis-alignment of rolls, the result is a bulge on the baaaar which is rolled into the metal and is lapped over. It remains throughout subsequent working and appears as a longitudinal crack.

Rolling Mandrel - In ring rolling, a vertical roll of sufficient diameter to accept various sizes of ring blanks and to exert rolling force on an axis parallel to the main roll.

Rolling Over - The operation of reversing the position of a flask. If the drag part of the pattern has been rammed with the parting surface downward, it is rolled over 180 degrees to allow core setting and placement of cope.

Rolling Slab - A rectangular semi-finished product, produced by hot rolling fabricating ingot and suitable for further rolling.

Rolling Ticket - The order matte, order paper, and mill order paper; tells how coil should be rolled or processed.

Rollover Board - A wood or metal plate on which the pattern is laid top face downward for ramming the drag half mold, the plate and half mold being turned over together before the joint is made.

Rollover Machine - A molding machine with which the flask is rolled over before the pattern is drawn from the mold.

Roofing Sheet - Coiled or flat sheet in specific tempers, widths and thickness suitable for the manufacture of corrugated or v-crimp roofing.

Root Diameter - See minor diameter.

Roping - A rope-like appearance in the rolling direction after the metal has undergone severe deformation

Rosin Powder - Powder used on reels to ensure a tight start and prevent slippage.

Rotary Shear (Slitting Machine) - A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil. NOTE: cutter discs are also employed in producing dircles from flat sheets but with differently designed machines.

Rotary Strainer - A second stage in-line water filter for water delivered from the New Blowing Room Pump to the Blast Furnace. The strainer contains an electric-driven rotary sieve that catches particulates and prevents them from entering the water system.

Rotoweigh - An electronic scale mounted to the lifting block of a crane used to weigh scrap and coils. A weight readout is displayed on the side of the crane cab.

Roughting - The fast removal of stock to reduce a workplace to approximate dimensions, leaving only enough material to finish the part to specifications.

Roughing Stand - The first rolling stand through which metal passes during hot rolling. Once reduced by the roughing stands, the metal continues on to the finishing stands where smoother rolls with a smaller gap are used to complete the hot roll process.

Roundness - This term is not recommended. The term Ovality is prferred.

Route - The system of transport for moving any piece of inventory from a source location to any destination includes the physical path as well as the mover/hauler chosen to transport.

Ru - Chemical symbol for Ruthenium

Rub Mark - See Mark Rub.

Rub, Tool - A surface area showing a scratch or abrasion resulting from contact of the hot extrusion with the press equipment

Rubber Id's - Inserts used to change the center diameter (20"-24" ID).

Rubber Roll - A roll in the line mainly used as a wringer roll or back-up roll.

Rule, Hook - A rule with a hook on the end for measuring through pulley holes and in similar places.

Ruling Section - More accurately termed limiting ruling section. One of the most important factors associated with the choice of steel for a given purpose is to ensure that the desired mechanical properties are abtained throughout the section when the material has been heat treated. The limiting ruling section determines the maximum diameter or cross-section of a bar or component in which the specified properties can be achieved by a given heat treatment. The analysis of the steel also has an important bearing on this.

Runner - A channel through which molten metal or slag is passed from one receptacle to another; in a mold, the portion of the gate assembly that connects the downgate or sprue with the casting ingate or riser. The term also applies to similar portions of master patterns, pattern dies, patterns, investment molds and finished castings.

Runner Extension - In a mold, that part of a runner which extends beyond the farthest ingate as a blind end. It acts as a dirt trap since the first rush of metal along the runner will pick up any loose particles of sand or dirt and carry them into the extension and not into the mold cavity.

Runner Riser - A conventional runner, usually in the horizontal plane, which permits flow of molten metal to the ingate and is large enough to act as a reservoir to feed the casting.

Running Pump - A pump in a hydraulic system that is being used to create pressure.

Runout - A casting defect caused by incomplete filling of the mold due to molten metal draining or leaking out of some part of the mold cavity during pouring; escape of molten metal from a furnace, mold or melting crucible.

Rust - A visible corrosion product consisting of hydrated oxides of iron. Applied only to ferrous alloys.

Ruthenium - Chemical symbol Ru. A white metal noted for its harness; the most expensive of the platinum group

Ragged Edges - Edges of Sheet or Strip which are torn, split, cracked, ragged or burred or otherwise disfigured.

Reciprocal Lattice (for a crystal) - A group of points arranged about a center in such a way that the line joining each point of the center is perpendicular to a family of planes in the crystal, and the length of this line is inversely proportional to their interplanar distance.

Recovery - Reduction or removal of work-hardening effects, without motion of large-angle grain boundaries.

Recovery - (1) The removal of residual stresses by localized plastic flow as the result of low-temperature annealing operations; performed on cold worked metals without altering the grain structure or strength properties substantially.

Recrystallization - A process whereby a distorted grain structure of cold worked metals is replaced by a new, stress-free grain structure as a result of annealing above a specific minimum temperature for a specific time.

Recrystallization - (1) The change from one crystal structure to another, as occurs on heating or cooling through a critical temperature. (2) The formation of a new, strain-free grain structure from that existing in cold worked metal, usually accomplished by heating.

Recrystallization - (1) A change from one crystal structure to another, such as that occurring on heating or cooling through a critical temperature. (2) Formation of a new, strain-free grain, structure from the structure existing in cold worked metal.

Recrystallization Temperature - The approximate minimum temperature at which complete recrystallization of a cold worked metal occurs within a specified time.

Recystallization Annealing - Annealing cold worked metal to produce a new grain structure without a phase change.

Red Shorness - Brittleness in steel when it is red hot.

Reduction of 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. (2) The difference, expressed as a percentage of original area, between original cross-sectional area and that after straining the specimen.

Refining Temperature - A temperature, usually just higher than the transformation range, employed in the heat treatment of steel to refine the structure -- in particular, the grain size.

Refractory - A heat-resistant material, usually nonmetallic, which is used for furnace linings and such.

Refractory Alloy - A term applied to those alloys which due to hardness or abrasiveness present relative difficulty in maintaining close dimensional tolerances.

Residual Elements - Small quantities of elements unintentionally present in an alloy.

Residual Stress - Macroscopic stresses that are set up within a metal as the result of non-uniform plastic deformation. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.

Residual Stress - Stress present in a body that is free of external forces or thermal gradients.

Residuals - 'Incidental' or 'tramp' elements not named in a specification. These inclusions are usually due to contaminated scrap.

Resilience - The tendency of a material to return to its original shape after the removal of a stress that has produced elastic strain.

Resistance Welding - Welding with electrical resistance heating and pressure, the work being part of an electrical circuit.

Resolution - The capacity of an optical or radiation system to separate closely spaced forms or entities; also, the degree to which such forms or entities can be discriminated.

Ribbon Wound - A term applied to a common method of winding strip steel layer upon layer around an arbor or mandrel.

Riffles - Waviness at the edge of sheet or strip.

Rimmed Steel - Low-carbon steel containing sufficient iron oxide to produce continuous evolution of carbon monoxide during ingot solidification, resulting in a case or rim of metal virtually free of voids.

Rimmed Steel - A low-carbon steel containing sufficient iron oxide to give a continuous evolution of carbon monoxide while the ingot is solidifying, resulting in a case or rim of metal virtually free of voids. Sheet and strip products made from the ingot have very good surface quality.

Ripple (defect) - A slight transverse wave or shadow mark appearing at intervals along the piece.

Roll Forming - An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called molded sections.

Rolled Edges - Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.

Rolled In Scale - A surface defect consisting of scale partially rolled into the surface of the sheet.

Roller Leveling - Leveling by passing flat stock through a machine having a series of small-diameter staggered rolls.

Rolling - Reducing the cross-sectional area of metal stock, or otherwise shaping metal products, through the use of rotating rolls.

Rolling - A term applied to the operation of shaping and reducing metal in thickness by passing it between rolls which compress, shape and lengthen it following the roll pattern.

Rolling Direction (in rolled metal) - The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.

Rolling Mills - Equipment used for rolling down metal to a smaller size or to a given shape employing sets of rolls the contours of which determine or fashion the product into numerous intermediate and final shapes, e.g., blooms, slabs, rails, bars, rods, sections, plates, sheets and strip.

Rough Machining - Machining without regard to finish, usually to be followed by a subsequent operation.

Rule Die Steel - A hardened and tempered medium high carbon spring steel strip sufficiently low in hardness to take moderately sharp bends without fracture, intended for manufacture into rule dies for the purpose of cutting or stamping fabrics, paper, cardboard, plastics, and metal foil into desired shape.