D (Fordath) Process - Shell molding in which the shell is made by blowing sand into a box like heated structure so that a shell of controlled thickness is created.
Damper Roll - A roll used to control the line tension on the plate.
Dampers - (various types) Scrubber isolation damper, emergency stack cap damper, fuel air damper.
Datum Plane - In layout and machining operations the reference plane from which dimensions are measured in the perpendicular direction.
Datum Points - In layout and machining operations the reference points on a datum plane from which dimensions are measured.
Daubing - Filling of cracks in molds or cores by specially prepared pastes or coatings to prevent a mechanical penetration of metal into these cracks during pouring. Also, the final plastering or coating of the cupola or ladle after shrinkage has taken place during the drying period. Clay slurry or clay wash with various coating compounds are applied.
dB - Decibel
DC - The second of the two types of electricity. It stands for direct current. In a DC circuit, current is always flowing in the same direction and (for a given voltage) is of the same magnitude.
DC (Direct Chill) Casting - A continuous method of making ingots or billets for sheet or extrusion by pouring the metal into a short mold. The base of the mold is a platform that is gradually lowered while the metal solidifies, the frozen shell of metal acting as a retainer for the liquid metal below the wall of the mold. The ingot is usually cooled by the impingement of water directly on the mold or on the walls of the solid metal as it is lowered. The length of the ingot is limited by the depth to which the platform can be lowered; therefore, it is often called semicontinuous casting.
DC (Direct Chill) Casting - A continuous method of making ingots or billets or extrusion by pouring the metal into a short mold. Some times called semi-continuous casting.
Dead Annealing - See Annealing
Dead End - The end of a water line, the point where the flow stops.
Dead Flat - Perfectly flat. As pertaining to sheet, strip or plate. Refer to Stretcher Leveling.
Dead Smooth - The term applied to the finest cut of a file.
Dead Steel - Fully killed steel, also applied to steel which fails to respond to heat treatment.
Deadburned - Term applied to refractory materials obtained by calcimining at a temperature high enough to form a product inert to atmospheric moisture and carbon dioxide, and less apt to contract.
Deadburned Dolonite - Dolonite burned at high temperature with additions of an agent, such as oxide of iron.
Deadhead - (DH) Deadheading is to run a coil through a stand with the rolls open; no reduction in gauge.
Deburr - To remove sharp edges.
Deburris - Horizontal knife used to remove burrs after slitting.
Decalescence - A term used in reference to the absorption of heat without a corresponding indrease in temperature, when steel is heated through the ctitical points (phase changes).
Decant - 1) Pour from one vessel to another, 2) pour off molten metal without disturbing the sludge.
Decarburization - The loss of carbon from the surface of steel by heating above lower critical temperature or by chemical action. Decarburization is usually present to a slight extent in steel forgings. Excessive decarburization can result in defective products.
Decibel (dB) - Unit for measuring the ration amounts of acoustical power; one-tenth of a bel.
Decoration (of dislocations) - Segregation of solute atoms to the line of a dislocation in a crystal. In ferrite, the dislocations may be decorated with carbon or nitrogen atoms.
Dedendum - The depth or that portiono of a gear tooth from the pitch circle to root circle of gear.
Deep Drawing - The fabrication process of flat rolled steel to make drawn parts. The part is mechanically formed through or in a die. The blank diameter is reduced; the blank contracts circumferentially as it is drawn radially inward. (See Deep Drawing Applications).
Deep Drawing Applications - Parts/applications that require deep drawing in their fabrication. Examples are motor shells, fenders, quarter panels, door panels.
Deep Etching - Macroetching; etching for examination at a low (less that 10X) magnification, in a reagent that attacks the metal to a much greater extent than normal for microscopic examination. Gross features my be developed; i.e., abnormal grain size, segregation, cracks, or grain flow.
Deepbed Filter - A gas filter in air pollution control, consisting of a loosely packed mat of fibrous materials; not practical where high grain loading are encountered.
Defect - 1) Anything that renders the steel unfit for the specific use for which it was ordered. What is defective for one customer may be prime steel for another. 2) A variety of quality problems in a coil. Examples are punchmarks, roll marks, oil spots, and scratches.
Deflector Roll - A roll used to change the direction of the strip.
Deformation Test - An AGS test using an instrument such as the Dietert Universal Sand-Strength Testing machine (with deformation accessory) to determine the amount in inches that the sand specimen is compressed before it ruptures.
Degas Heat - A heat of degas steel is a heat that is produced to extremely low carbon levels through vacuum degassing.
Degasser - A material employed for removing gases from molten metals and alloys.
Degassing - Usually a chemical reaction resulting from a compound added to molten metal to remove gases from the metal. Often inert gases are used in this operation.
Degassing Flux - A flux for removing gas from the melt.
Degenerate Structure - Usually refers to pearlite that does not have an ideally lamellar structure. The degree of degeneracy may vary from slight perturbations in the lamellar arrangement to structures that are not recognizably lamellar.
Degreasing - Removal of grease,oil or other lubricant-type materials by immersion in an effective solvent. primarily alkaline cleaners are used,although an organic solvents are useful.
Degree of Ramming - The extent of hardness to which a sand mold is rammed.
Delay Code - A four-character code used to identify the type and reason for a delay.
Delay Screen (Skim Gate (Erroneously),Skim Strainer) - A small piece of perforated light gage tinned sheet steel, or of copper, aluminum, and/or magnesium alloys, frequently placed in the pouring basin at the top of the downsprue. It delays the flow of metal long enough to allow the basin to fill before it melts to permit only clean metal from the bottom of the basin to enter the downsprue. Delay screens are also use elsewhere in the gating system.
Delivery End - The exit end of the line.
Delivery Tail End The outside - The outside lap of the produced coil on the delivery reel.
Delta Iron - Allotropic modification of iron, stable above 2552 (degrees) F. to melting point. It is of body-centered cubic crystal structure.
Demineralization Train - Two units, a cation tank and an anion tank, working in conjugation. Water flows through the tanks and undergoes a positive and negative ion exchange that removes hardness.
Demineralized Water - City water which is circulated through a series of three demineralizing filters to soften it and remove residuals. It is then delivered to a storage tank for use in overflowing the superheater elements and headers on the boiler during hydrostatic tests. Filling the superheaters with demineralized water prevents the raw water used in a hydrostatic test from entering the superheaters where it could cause corrosion problems.
Densitometer - Instrument utilizing the photoelectric principle to determine the degree of darkening of developed photographic film.
Density - The mass per unit volume of a substance, usually expressed in grams per cubic centimeter or in pounds per cubic foot.
Density (Photographic) - Density is used to denote the degree of darkening of photographic film. Logarithm of opacity of exposed and processed film. Opacity is the reciprocal of transmission; transmission is the ratio of transmitted to incident intensity.
Deoxidation - (1) Removal of oxygen from molten metals by use of suitable chemical agents. (2) Sometimes refers to removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them.
Deoxidizing - Removal of oxygen. In steel sheet, strip, and wire technology, the term refers to heat treatment in a reducing atmosphere, to lessen the amount of scale.
Dephosphorization - Elimination of phosphorus from molten steel.
Depth Card - A notched paper card used in setting the depth of the knives.
Depth of fusion - The depth to which base matel melts during welding
Dermatis - An inflammation of the skin, which may be caused by allergy to certain casting adjuncts, as resins; particularly in the shell process.
Descale - Remove the fire scale from the surface of casting.
Descaling - The process of removing scale from the surface of steel. Scale forms most readily when the steel is hot by union oxygen with iron. Common methods of descaling are (1) crack the scale by use of roughened rolls and remove by a forceful water spray, (2) throw salt or wet sand or wet burlap on the steel just previous to its passage through the rolls.
Deseaming - A process of burning out defective areas on the surface of ingots,blooms or billets. The condition of the surface is such that it can then be rolled or forged intoa saticfactory product.
Design Base Line - The noise spectrum which is the goal of any particular noise reduction program.
Designations - Type of metal named, as steel, malleable, nonferrous, etc.
Deslagger - A rotating retractable steam lance used to remove slag from the boiler tubes and walls.
Despersion Hardening - "Hardening by the formation of hard microconstituents dispersed in a softer matrix. See Preciptitation Hardening "
Desulfurization - Operation that injects a chemical mixture into a ladle full of hot metal to remove sulfur prior to its charging into the Basic Oxygen Furnace. Sulfur enters the steel from the coke in the blast furnace smelting operation, and there is little the steelmaker can do to reduce its presence. Because excess sulfur in the steel impedes its welding and forming characteristics, the mill must add this step to the steelmaking process.
Desulfurizer - A material used to remove sulfur from molten metals and alloys. Also, a form of holding ladle or basin in which the molten metal and desulfurizing material are brought into contact.
Desuperheater - Pressure reducing station which reduces 800 psi high pressure steam to 225 psi low pressure steam to supplement the low pressure system throughout the mill.
Detroit Cup Test - A cupping test for sand, using a steel ball as plunger, the depth of cup being shown on a dial
Developed Hardness - Hardness capability of a metal or alloy after a hardening heat-treating process.
DeVries Test - A test to give the relative hardness of deep hardening steels.
Dew Point - The dew point of the atmosphere inside the furnace. The higher the negative number, the dryer the furnace. A dry furnace is desired.
Dewaxing - The process of melting out the expendable was pattern from an investment mold by the application of heat, usually at temperatures less than 250 B0F (121) B0C).
Dexidation - Removal of excess oxygen from molten metal, usually accomplished by adding materials with a high affinity for oxygen, the oxides of which are either gaseous or readily form slags.
Dextrin - Soluble gummy carbohydrate formed by the decomposition of starch by heat, acids, or enzymes; it is use din core compounds, mold compounds, mold washes, core pastes, and other compounds requiring high dry compressive strengths.
Dezincing - A coating defect consisting of the removal of the zinc oxide in a "C" enamel film by chemical reaction with food products. Dezincing appears as a lack of opacity in the film and usually occurs in a random pattern.
Dezurik Valve - Butterfly or slide-plate type stop valve that allows emergency quencher and quencher flow to the bull nozzle of the ductwork. Name refers to manufacturer.
De E6rator Tanks - Treated water storage tanks which help remove excess air from the feed water by spraying the water into an atmosphere of exhaust steam as it enters the tank. Removal of all possible air helps prevent corrosion of the boiler internals. From the tanks, the feed water is pumped to the boilers at approximately 950 psi.
Dia-Tester (Wolpert Hardness Tester) - A hardness testing machine using the Vickers or Brinell ball indenter.
Diameters - In microscopy, an indication of the amount of magnification. 1000 diameters 3D1000 times original size.
Diametral Pitch - Ratio of the number of teeth on a gear to the number of inches of pitch diameter or the number of teeth to each inch of pitch diameter.
Diammonium Phosphate - Used to fireproof clothing of foundry workers.
Diamond Pyramid Hardness Test - This test, more commonly known as the vickers test finds greater use in the laboratory than the workshop. It employs a pyramid shaped diamond with an included angle of 136 which is impressed into the specimen using loads of 5 to 120 kg making a small square impression. This test is used for finished or polished components because the impression can be very small. The diamond pyramid hardness number is obtained from a calculation based on measuring the diagonals of the impressions in the steel.
Diaphragm Shell Molding Machine - An arrangement for applying a squeeze pressure with a high-temperature silicone rubber diaphragm.
Diaspore Clay - A rocklike mineral consisting chiefly of diaspore (HAlO2) bonded by fire clay substance with an alumina content higher than 63%.
Diathermometer - An instrument for examining the thermal resistance or the heat conducting power of objects.
Diatomaceous Earth (Infusorial Earth) - A hydrous of silica which is soft, light in weight and consists mainly of microscopic shells of diatoms or other marine organisms.
Die - A metal block used in forming materials by casting, molding, stamping, threading, or extruding.
Die Assembly - The parts of a die stamp or press that hold the die and locate it for the punches.
Die Casting (Brit. Pressure Die Casting) - A rapid, water-cooled permanent mold casting process limited to nonferrous metals. There are three types: the plunger-type operated hydraulically, mechanically or by compressed air with or without a gooseneck; the direct-air injection which forces metal from a goose-neck into the die, and the Cold-Chamber Machine. All force the metal into the die with a pressure greater than that of gravity flow.
Die Cavity - The impression in a die into which pattern material is forced.
Die Coating - See Release Agent
Die Insert - A removable liner or part of a die body or punch.
Die lines - Longitudinal marking which may be imparted to the surface of an extrusion by irregularities in a die aperture
Die Set - In stamping, the parts of the press that hold the die and locate it in proper relation to the punches.
Die Shift - The impression of the top die not being in alignment with the impression of the bottom die, also, the amount of misalignment.
Die-Cleaning Area - A section of the coating of the strip which is produced when the Operator cleans the die.
Dielectric Oven (Dryer) - A rapid-drying high frequency electric oven used to bake cores.
Dies - (Galvanize) Air pressure devices in the Sheet Mill which, depending on distance from coil, determine coating thickness by removing excess metal from the strip; the farther the die is from the steel, the heavier the coating - also called "knives" on this line.
Die Stock - The frame and two handles (bars) which hold the dies (chasers) used for cutting (chasing) external screw threads.
Dietert Process - A patented process for the production of precision molds involving blowing a contoured core around a pattern to form half a mold.
Dietert Tester - A patented apparatus for the direct reading of a Brinell hardness after impression without using magnification or conversion tables.
Differential Coatings - Coatings on flat rolled products whereby the thickness of the coating on the one side is heavier than the other side. At Weirton Steel, the term is applied to a tin plate product which requires one side of the steel to have a heavier tin coating than the other side.
Differential Heat Treatment - A heating process by which the temperature is varied within the object so that, after cooling, various parts may have different properties as desired.
Diffuser - X-ray equipment, a portion of the condensing and focusing system that permits even distribution of energy.
Digital Level Indicator - Devices that electronically measures the level of oil in a tank. The readout is given in a percentage of the tank that is full (100%).
Dike - A patented flexible seal to prevent blow-by in core boxes.
Dimensional allowance - The specified diffferance in size between mating parts
Dimensional Tolerance Grades - A system of classifying the tightness of tolerances for the purpose of defining accurately the tolerances involved, and for simplifying the communication process between customer and producer regarding what is wanted, and what is possible, respectively.
Dimentional Tolerance - A range by which a product's width and gauge can deviate from those ordered and still meet the order's requirements. (Also See Commercial Tolerance)
Dip Coat - "In solid and shell mold investment casting, a fine ceramic coating applied as a slurry to the pattern to produce maximum surface smoothness, followed by a cheaper conventional investment. See Investment Precoat "
Dip Tank - A tank, preferably lined with rubber, epoxy, or other nonmetallic, into which diecastings are dipped for cooling after leaving the machine.
Dipped Joint - A thin joint made by dipping of the brick in a thin mortar.
Direct Blowing - The term used when one blower is blowing to one furnace at a time.
Direct Casting - Teeming from the ladle into the casting mold without the use of a tundish.
Direct Reduced Iron (DRI) - "WHAT Processed iron ore that is iron-rich enough to be used as a scrap substitute in electric furnace steelmaking. WHY As mini-mills expand their product abilities to sheet steel, they require much higher grades of scrap to approach integrated mill quality. Enabling the mini-mills to use iron ore without the blast furnace, DRI can serve as a low residual raw material and alleviate the mini-mills' dependence on cleaner, higher-priced scrap. HOW The impurities in the crushed iron ore are driven off through the use of massive amounts of natural gas. While the result is 97% pure iron (compared with blast furnace hot metal, which, because it is saturated with carbon, is only 93% iron), DRI is only economically feasible in regions where natural gas is attractively priced. "
Direct-Arc Furnace - An electric arc furnace in which the metal being melted is one of the poles.
Direct-reduced iron - (DRI) A metallic iron product made from iron ore pellets, lumps or fines that is reduced (by removing only the oxygen) from the ore at a temperature below the melting point of the iron. DRI is used as feedstock in electric-arc furnaces, blast furnaces and in other iron and steelmaking processes.
Directional Solidification - The solidification of molten metal in a casting in such a manner that liquid feed metal is always available for that portion that is just solidifying.
Dirt Trap - "A well employed in a gating system to entrap the first metal poured, which may contain dirt or unwanted particles (ineffective). See Slag Trap "
Dirty Casting - A casting containing an excessive amount of nonmetallic inclusions in the body of the metal.
DIS - Ductile Iron Society
Disappearing Filament Pyrometer (Optical Pyrometer) - A telescope in which a hot body is viewed through an eyepiece; temperature is measured by the matching color of a calibrated lamp filament with color of hot metal.
Discharge Valve On a Pump - A valve that isolates a pump from the rest of the pumping system.
Discoloration - A change in the visual appearance of the material caused by formation of oxides when exposed to contaminating atmosphere, always at elevated temperatures.
Disconnect - Mechanical device, resembling a large knife switch, that is used as a safety device for isolating electrical equipment.
Dish - A concave surface departing from a straight line edge to edge. Indicates transverse or across the width.
Distributor (See SERVICE CENTER) -
Dispersed Shrinkage - Small shrinkage cavities dispersed through the casting, which are not necessarily cause for rejection.
Dissolved Carbon - Carbon in solution in steel in either the liquid or solid state.
Distorted Pattern - A pattern untrue to the specified dimensions.
Distortion - See Warpage
Distribond - A siliceous clay containing Bentonite used as bond in molding sands.
Distribution, Sand Grain - Variation or uniformity in particle size of a sand aggregate when properly screened by U.S. Standards screens.
Distributor (See SERVICE CENTER) -
Distruptive Strength - Maximum strength of a metal when subjected to three principal tensile stresses at right angles to one another and of equal magnitude.
Disturbed Metal - The cold worked metal formed on a polished surface during the processes of grinding and polishing.
Ditch Valve - A valve for controlling high pressure raw water jets. The jets wash the ash from the sluice way to the ash pump hole.
Diversion - 1.) A situation that occurs when a coil/s intended for an order doesn't meet quality standards or customers specifications and is therefore diverted to meet another customer's specifications. In addition, coils can be diverted to complete another customer's order or for other reasons as necessary. 2) Removing a product from it's original order. Synonymous with Reapplication.
Diverted Coil - (DRV) A coil that is no longer being sent to its original order but is being sold elsewhere.
Dividers, Springs - Dividers whose legs are held together at the hinged end by the pressure of a c-shaped spring.
Dividing Head (index bead) - A machine tool holding fixture which positions the work for accurately spacing holes,slots,flutes and gear teeth and for making geometric shapes. When geared to the table lead screw, it can be used for helical milling operations.
Divorced Pearlite (Granular Perlite, Spheroidite, Spheroidized Cementite) - Pearlite in which the cementite has been spheroidized by prolonged annealing just below the Ac1 point, or by annealing at the same temperature after cold working.
Doctor Blade Steel Strip - A hardened and tempered spring steel strip, usually blued, produced from approximately .85 carbon cold rolled spring steel strip specially selected for straightness and good edges. Sometimes hand straightened or straightened by grinding and cur to desired lengths. This product is used in the printing trade as a blade to uniformly remove excess ink (dope) from the rolls; hence its name.
Do-All-Saw - A trade name given to a type of band saw used for sawing metal.
Dog - A clamping device (lathe dog) used to drive work being machined between centers. Also, a part projecting on the side od a machine worktable to trip the automatic feed machanism off or to reverse the travel.
Doghouse - Structure on the BOP roof where the junction header power relief vents through to the atmosphere.
Dolomite - A material that is used to add magnesium oxide to the sinter.
Dose - A quantity of radiation measured at a certain point expressed in roentgens, rems or rads.
Dose Meter, Integrating - Ionization chamber and measuring system designed for determining total radiation administered during an exposure. In medical radiology the chamber is usually designed to be placed on the patient's skin. A device may be included to terminate the exposure when it has reached a desire value.
Dose Rate - Dose per unit time.
Dose, Exposure - Quantity of radiation measured in air in roentgens without backscatter at a given point.
Dosimeter - "Instrument used to detect and measure an accumulated dosage of radiation; in common usage it is a pencil-size ionization chamber with a built-in self-reading electrometer; used for personal monitoring. See Dosimeter, Pocket "
Dosimeter, Pocket - A pocket ionization chamber containing it own electrometer. An auxiliary charging device is usually necessary.
Double (Cold) Reduced (DR) - 1) Material that has been cold reduced in thickness twice. The first reduction is at the tandem Mill (where it is reduced at five different locations) and the second is at the Weirlite Mill. 2) Plate given a second major cold reduction following annealing. Double reduced products are relatively hard, have limited ductility, and highly directional mechanical properties. Aim Rockwell hardness 30T hardness is 76; Aim yield strength (varying from materials) is 80,000 psi to 90,000 psi; approximate tensile strength is 90,000 psi.
Double Annealing - As applied to hypoeutectoid steel, a process of heating to above the upper critical point (AC3) and holding at that temperature until complete solution of the carbide has been achieved then cooling rapidly and reheating immediately to above A3 and slowly cooling.
Double Impression Method - A way of determining approximate Brinell hardness by placing a hardened steel ball between a specimen of known hardness and the metal to be tested and pressurizing in an arbor press.
Double Skin (bottom Splash, Ingot Shell, Plaster) - A defect consisting of a secondary layer of metal sometimes found on top-poured ingots.
Double Tempering - A retempering operation sometimes necessary for steel containing retained austenite which breaks down during cooling from the first tempering to form a new and hence untempered martensite.
Doublebruned - Deadburn; not be mistaken for two firing.
Doughnut - A venturi system that creates a draft with jets of water that draws the molten slag from the spout and to the sluiceway.
Dove-tail - An interlocking connection frequently used for the assembly of interlocking extrusions; it is assembled by a sliding action
Dowel - 1) a wooden or metal pin of various types used in the parting surface of parted patterns and core boxes, 2) in diecasting dies, metal pins to ensure correct registry of cover and ejector halves.
Downcomers - Hollow pipes that allow the plater solution to return from the plater cells to the distribution tank.
Down Feed (climb cutting, climb milling) - A seldom used method of feeding work into milling cutters. The work is fed in the same direction as the portion of the cuttere which comes in contact with it.
Downgate - See Downsprue
Downhand Welding - Welding deposited along a horizontal line and surface.
Downsprue (Sprue, Downgate) - The first channel, usually vertical, which the molten metal enters; so called because it conducts metal down into the mold.
Downtime - Time lost from normal casting activity, due to unscheduled interruptions.
DQ - Draw quality 3D more flexible grade of steel.
Draft - The measured positive or negative pressure maintained within the boiler and produced by the use of forced draft and induced draft fans. Negative draft helps ensure that the fire and exhaust gases are controlled within the boiler.
Draft, Pattern - See Pattern Draft
Drag - Lower or bottom section of a mold or pattern.
Drain Line - Any hose, pipe or tube connected to a valve that is opened to remove oil pressure from a system or a component of a system.
Drain Valve - A valve that is opened to remove oil pressure from a system or a component of a system.
Draw - A term used for 1) to temper, 2) to remove pattern from mold, 3) an external contraction defect on surface of mold.
Drawing - Forcing metal through a die by pulling it. (pushing metal through a die is called extrusion) Small tube, wire, or pipe is commonly made by drawing down a larger extruded size
Draw Peg - A wooden peg used for drawing patterns.
Draw Plate - A plate attached to a pattern to facilitate drawing of a pattern from the mold.
Draw quality - More flexible grade of steel
Draw Screw - A threaded rod with an eye screwed into a pattern to enable it to be drawn from the mold.
Draw Spike - A steel spike used to rap and draw a pattern from the sand; it is driven into the wood of the pattern, as opposed to a Draw Screw, which threaded.
Draw-Redraw - (DRD) Two-piece. Process for making two-piece cans in which a circular blank is drawn into a die to form a shallow cup and then is redrawn on a second or third die to produce a can body of the desired dimensions. Plate is coated prior to the forming process.
Draw-Thin-Redraw - (DTR) An enhancement of the DRD process for making two-piece can body utilizing high tensile TFS that has an organic polymeric coating applied prior to the forming operations. The patented DTR process is a means of subjecting the coated feedstock to forming strains such that the metal and coating avoid compacting and subsequent sidewall burnishing, thus enhancing the integrity of the organic coating. The resultant sidewall is thinned during the drawing and redrawing operations, thus facilitating the specified can body dimensions using a smaller starting blank size than that required for DRD.
Drawing - (1) Forming recessed parts by forcing the plastic flow of metal in dies. (2) Reducing the cross section of wire or tubing by pulling it through a die. (3) A misnomer for tempering.
Drawing - "Removing pattern from the mold or mold from pattern in production work. See also Temper "
Drawing Quality - (DQ) Flat-rolled products produced from either deep drawing rimmed steel or extra deep drawing aluminum killed steels. Special rolling and processing operations aid in producing a product, which can stand extreme pressing, drawing or forming, etc., without creating defects.
Drawn - Mechanically formed by tension through or in a die.
Drawn & Ironed - (D&I) A process primarily used to manufacture two-piece beer or carbonated beverage can bodies, although some canned food product is packaged in steel D&I can bodies. An appropriately sized circular disk is drawn into a cup to approximately the finished can diameter. The side wall height is created by forcing the cup through a series of rings, ironing the metal thinner than the starting material thickness. Can bodies are coated with organic lacquers after forming.
Drawn-Over-Mandrel - A procedure for producing specialty tubing using a drawbench to pull tubing through a die and over a mandrel, giving excellent control over the inside diameter and wall thickness. Advantages of this technique are its inside and outside surface quality and gauge tolerance. Major markets include automotive applications and hydraulic cylinders.
Dressing - The act of removing the glaze and dulled abrasives from the face of a ginding wheel to make it clean and sharp. See Truing.
Dried Sand - Sand which bas been dried by mechanical dryer prior to use in core making.
Drier (Dryer) - A material, as alcohol ammonium nitrate, sodium perborate and manganese oleate, added to a core or mold mixture to remove or reduce the water content.
Drift - Minimum ID clearance verified by pulling a mandrel of size throught a length of pipe.
Drill - A pointed tool that is rotated to cut holes in material.
Drill Bushing - A hardened steel guide inserted in jigs,fixtures or templates for the purpose of providing a guide for the drill in drilling holes in their proper or exact location.
Drill, Center - A combination drill and countersink.
Drill Chuck - A device used to grip and attach them to a rotating spindle.
Drill Jig - A jig which holds parts or units of a structure and by means of bushings,guides the drill so that the holes are properly located.
Drill Pipe - Pipe used in the drilling of an oil or gas well. Drill pipe is the conduit between the wellhead motor and the drill bit. Drilling mud is pumped down the center of the pipe during drilling, to lubricate the drill bit and transmit the drilled core to the surface. Because of the high stress, torque and temperature associated with well drilling, drill pipe is a seamless product.
Drill Press - A drilling machine with a counterbalanced spindle which makes it possible for the operator to control accurately the rate at which the drill is fed into the work. The sensitive drill press usually contains drills that are less than inch diameter and which rotate at high speeds.
Drill Rod - A term given to an annealed and polished high carbon tool steel rod usually round and centerless ground. The sizes range in round stock from .013 to 1 1/2 diameter. Commercial qualities embrace water and oil hardening grades. A less popular but nevertheless standard grade is a non-deforming quality. Drill Rods are used principally by machinists and tool and die makers for punches, drills, taps, dowel pins, screw machine parts, small tools, etc.
Drill Sleeve - An adapter with an internal and external taper which fits tapered shank tools such as drills or reamers to adapt them to a larger size machine spindle.
Drill Socket - An adapter similar to a sleeve except that it is made to adapt a larger tapered-shank tool to smaller size spindle.
Drill, Twist - A commonly used metal-cutting drill, usually made with two fluted running around the body.
Drillings, Test - Chips, or small particles of metal removed from a test specimen for chemical analysis.
Drip Tube - Small sight glasses used to check and adjust the rate of flow of drive oil.
Drive Fit - One of several classes of fits in which parts are assembled by pressing or forcing one part into another.
Drive Oil - Lubricating oil used on different components of the finishing mill.
Drive Oil Alarm - A warning received when drive oil pressure is low or pressure is stopped.
Drive Oil System - A system which encompasses all the components needed to deliver drive oil to the finishing mill. It consists of both #1 and #2 drive oils pumped from the roughing mill.
Drive Side - The side of the strip that is nearest to the drive motors that power the line.
DRL - Double random length-line pipe with a 35+ average lengths
Drop (Dropout) - A casting defect caused by sand dropping from the cope or other overhanging section.
Drop Ball - A heavy weight, usually ball or pear shaped, dropped from a height to break large pieces of metal scrap. Also used to strengthen warp castings.
Drop Gate - A term for a pouring gate or runner leading directly into the top of the mold.
Drop Off or Drop Out - "Sand falling from the Cope of a mold. See Drop "
Dross - Sediment which settles in bottom of the ZINC pot on the galvanize line. Also top dross, which floats on surface of pot and is skimmed off. A different type of dross also occurs on the top of the zinc pot, which is skimmed off on a regular time frame.
Drum Heads - Removable hinged man-way cover on both ends of a boiler drum.
Drum Ladle - A cylindrical refractory-lined ladle that is completely enclosed. A removable cover at the pouring spout permits addition of molten metal.
Drum Pusher - Device used to remove a steel drum from the entry coil traverse car.
Drum Vent - Manual valve that is used to relieve pressure on drums.
Drum, Magnetic - An electrically energized pulley or drum used for removing magnetic materials from sand, nonferrous borings and turnings, etc.
Dry Analysis - A term applied to spectrographic analysis.
Dry and Baked Compression Test - An AFS test to determine the maximum compressive stress that a baked sand mixture is capable of developing.
Dry Film Weight - Dry coating film weight is normally calculated in grams per square meter(gm/m B2) or milligrams per square inch(mg/in B2). Accurate control of dry film weight is essential to ensure that the coating material will possess its intended properties of physical and chemical resistance.
Dry Pan - A grinding machine of heavy rollers or millers testing on a bed. Screens or slits allow fine material to pass through.
Dry Permeability - The property of a molded mass of sand bonded or unbonded, dried at 220-230 B0F (105-110 B0C) and cooled to room temperature that allows passage of gases resulting during pouring of molten metal into a mold.
Dry Run - The process of checking the control panel to assure that all controls are functioning properly.
Dry Sand Casting - The process in which the sand molds are dried at above 212 B0F (100 B0C) before using.
Dry Sand Core - See Core
Dry Sand Mold - A mold from which the moisture has been removed by heating.
Dry Strength, or Dry Bond Strength - The maximum compressive, shear, tensile, or transverse strength of a sand mixture which has been dried at 220 to 230 B0F (105 to 110 B0C) and cooled to room temperature.
Dryer - Dries the strip after a rinsing process.
Dryer, Core - See Core Driers
Dryer, Dielectric - See Dielectric Oven
Dual Metal Centrifugal Casting - Centrifugal castings produced by pouring a different metal into the rotating mold after the first metal poured.
Ductile Iron - See Nodular Iron
Ductile Iron Society - See Ductile Iron Society for address
Ductility - Ability of steel to undergo permanent changes in shape without fracture at room temperature.
Ductwork - Ducts that carry exhaust solids from the boilers to the scrubber area.
Dummy block - A tight-fitting steel block placed between the ram and the billet in an extrusion press to prevent metal from leaking backward along the ram during extrusion.
Dumping - Dumping occurs when imported merchandise is sold in, or for export to, the domestic market at less than the normal value of the merchandise, i.e., a price which is less than the price at which identical or similar merchandise is sold in the comparison market, the home market (market of exporting country) or third-country market (market used as proxy for home market in cases where home market cannot be used). The normal value of the merchandise cannot be below the cost of production.
Dumping Margin - The amount by which the normal value exceeds the export price or constructed export price of the subject merchandise.
Dumping Valve - A type of single solenoid valve that when energized will open to quickly release the pressure in a hydraulic cylinder.
Dunker Roll - A roll used in the tanks that keeps the strip going through the tank.
Duplex - A category of stainless steel with high amounts of chromium and moderate nickel content. The duplex class is so named because it is a mixture of austenitic (chromium-nickel stainless class) and ferritic (plain chromium stainless category) structures. This combination was originated to offer more strength than either of those stainless steels. Duplex stainless steels provide high resistance to stress corrosion cracking (formation of cracks caused by a combination of corrosion and stress) and are suitable for heat exchangers, desalination plants, and marine applications.
Durability - The ability to accept permanent deformation.
Dust - Small solid particles created by the breaking up of larger particles by an process.
Dye Penetrant Inspection - A method for detecting surface porosity or cracks in metal. The part to be inspected is cleaned and coated with a dye which penetrates any flawa that may be present. The surface is wiped clean and coated with a a white powder. The powder absorbs the dye held in the defects indicating their location.
Dead Soft Annealing - Heating metal to above the critical range and appropriately cooling to develop the greatest possible commercial softness or ductility.
Dead Soft Steel - Steel, normally made in the basic open-hearth furnace or by the basic oxygen process with carbon less than 0.10% and manganese in the 0.20-0.50% range, completely annealed.
Dead Soft Temper - Condition of maximum softness commercially attainable in wire, strip, or sheet metal in the annealed state.
Deburring - A method whereby the raw slit edge of metal is removed by rolling or filing.
Decarburization - Removal of carbon from the outer surface of iron or steel, usually by heating in an oxidizing or reducing atmosphere. Water vapor, oxygen and carbon dioxide are strong decarburizers. Reheating with adhering scale is also strongly decarburizing in action.
Decarburization - Loss of carbon from the surface of a ferrous alloy as a result of heating in a medium that reacts with carbon.
Decarburization - The loss of carbon from the surface of a ferrous alloy as a result of heating in a medium that reacts with the carbon at the surface.
Deep Drawing - The process of cold working or drawing sheet or strip metal blanks by means of dies on a press into shapes which are usually more or less cup-like in character involving considerable plastic deformation of the metal. Deep-drawing quality sheet or strip steel, ordered or sold on the basis of suitability for deep-drawing
Deformative Bands - Generally, bands in which deformation has been concentrated inhomogeneously.
Degassing Process (In steel making) - Removing gases from the molten metal by means of a vacuum process in combination with mechanical action.
Dendrite - A crystal that has grown in treelike branching mode.
Dendrite - A crystal that has a tree-like branching pattern, being most evident in cast metals slowly cooled through the solidification range.
Dendritic Segregation - Inhomogeneous distribution of alloying elements through the arms of dendrites.
Die Sinking - Forming or machining a depressed pattern in a die.
Die-Lines - Lines of markings daused on drawn or extruded products by minor imperfections in the surface of the die.
Diffusion - (1) Spreading of a constituent in a gas, liquid or solid, tending to make the composition of all parts uniform. (2) The spontaneous movement of atoms or molecules to new sites within a material.
Dilatometer - An instrument for measuring the expansion or contraction of a solid metal resulting from heating, cooling, polymorphic changes, etc.
Dislocation - A linear defect in the structure of a crystal.
Drawing - (1) Forming recessed parts by forcing the plastic flow of metal in dies. (2) Reducing the cross section of wire or tubing by pulling it through a die. (3) A misnomer for tempering.
Drawing Back - Reheating after hardening to a temperature below the critical for the purpose of changing the hardness of the steel.
Drop Forging - A forging made with a drop hammer.
Drop Hammer - A forging hammer than depends on gravity for its force.
Dry Rolled Finish - Finish obtained by cold rolling on polished rolls without the use of any coolant or metal lubricant, of material previously plain pickled, giving a burnished appearance.
Ductile Crack Propagation - Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body.
Ductility - The ability of a material to deform plastically without fracturing, being measured by elongation or reduction of area in a tensile test, by height of cupping in an Erichsen test or by other means.
Ductility - The capacity of a material to deform plastically without fracturing.
Ductility - The property of metals that enables them to be mechanically deformed when cold, without fracture. In steel, ductility is usually measured by elongation and reduction of area as determined in a tensile test.
Duralumin - The trade name applied to the first aluminum-copper-magnesium type of age-hardenable alloy (17S), which contains nominally 4% Cu, 1/2% Mg. The term is sometimes used to include the class of wrought aluminum-copper-magnesium alloys that harden during aging at room temperature.
Duralumin (obsolete) - A term formerly applied to the class of age-hardenable aluminum-copper alloys containing manganese, magnesium, or silicon.