Glossary

F-L

Feather (Fin)

The thin projection formed on a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. by trimming or when the metal under pressure is forced into hairline cracks or dieThe machined recess in a die that gives the forging its shape. interfaces.

Fiber

A characteristic of wrought metal, including forgings, indicated by a fibrous or woody structure of a polished and etched section, and indicating directional propertiesProperties whose magnitude varies depending on the relation of the test axis to a specific direction within the metal or alloy.. FiberA characteristic of wrought metal, including forgings, indicated by a fibrous or woody structure of a polished and etched section, and indicating directional properties. Fiber is chiefly due to the extension of the constituents of the metal synonymous with flow lines and grain flow in the direction of working.... More is chiefly due to the extension of the constituents of the metal synonymous with flow linesPatterns in a forging resulting from the elongation of nonhomogeneous constituents and the grain structure of the material in the direction of working during forging; usually revealed by macroetching. See also Grain Flow. and grain flowFiber-like lines appearing on polished and etched sections of forgings that are caused by orientation of the constituents of the metal in the direction of working during forging. Grain flow produced by proper die design can improves the mechanical properties of forgings.... More in the direction of working.

Fillet

The concave intersection of two surfaces. In forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment., the desired radius at the concave intersection of two surfaces is usually specified.

Fin

The thin projection formed on a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. by trimming or when metal is forced under pressure into hairline cracks or dieThe machined recess in a die that gives the forging its shape. interfaces.

Finish

(1) The forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. operation in which the part is forged into its final shape in the finish(1) The forging operation in which the part is forged into its final shape in the finish die. If only one finish operation is scheduled to be performed in the finish die, this operation will be identified simply as finish; first, second, or third finish designations are so termed when one or more finish operations are to be performed in the same finish die. (2) The surface condition of a forging after machining. (3) The material machined off the surface of a forging to produce the finish machine component.... More dieThe machined recess in a die that gives the forging its shape.. If only one finish operation is scheduled to be performed in the finish dieThe machined recess in a die that gives the forging its shape., this operation will be identified simply as finish; first, second, or third finish designations are so termed when one or more finish operations are to be performed in the same finish die. (2) The surface condition of a forging after machining. (3) The material machined off the surface of a forging to produce the finish machine component.

Finish all over (F.A.O.)

A designation that a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. must have sufficient size over the dimensions given on the drawing(1) A forging operation in which the cross section of forging stock is reduced and the stock lengthened between flat or simple contour dies. See also Fullering. (2) in heat treating, the same as tempering. so that all surfaces may be machined in order to obtain the dimensions shown on the drawing. The amount of additional stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. necessary for machining allowanceSee Finish allowance. depends on the size and shape of the part, and is agreed on by the vendor and the user.

Finish allowance

The amount of stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. left on the surface of the forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. to be removed by subsequent machining. Also called “machining allowance” or “forging envelopeSee Finish Allowance..”

Finish trim

FlashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More removal from a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment.; usually performed by trimming, but sometimes by band sawing or similar techniques.

Finishing dies

The die setThe assembly of the upper and lower die shoes (punch and die holders), usually including the guide pins, guide pin bushings, and heel blocks. This assembly takes many forms, shapes, and sizes and is frequently purchased as a commercially available unit. Also, two (or, for a mechanical upsetter, three) machined dies used together during the production of a die forging.... More used in the last forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. step.

Finishing temperature

The temperatureThe temperature of the forging stock just prior to forging. at which hot mechanical working of a metal is completed or discontinued.

Flakes

Randomly oriented internal thermal cracksRuptures in metal set up by stresses due to thermal differentials. (“shatter cracks”) in steels resulting from critical combinations of stress and hydrogen content. In a fracture surface, flakesRandomly oriented internal thermal cracks ("shatter cracks") in steels resulting from critical combinations of stress and hydrogen content. In a fracture surface, flakes appear as bright silvery areas; on an etched surface they appear as short discontinuous cracks.... More appear as bright silvery areas; on an etched surface they appear as short discontinuous cracks.

Flame straightening

The correction of distortion in metal structures by localized heating with a gas flame.

Flange

A projecting rim or edge of a part; usually narrow and of approximately constant width for stiffening or fastening. See RibA relatively flat (but generally with draft) thin portion of a forging, generally perpendicular to the forging plane..

Flash

Metal in excess of that required to fill completely the blocking or finishing forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. of a set of diesThe metal blocks into which forging impressions are machined and from which forgings are produced.. FlashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More extends out from the body of the forging as a thin plate at the line where the diesThe metal blocks into which forging impressions are machined and from which forgings are produced. meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.

Flash extension

Portion of flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More remaining after trimming. Flash extensionPortion of flash remaining after trimming. Flash extension is measured from the intersection of the draft and flash at the body of the forging to the trimmed edge of the stock. is measured from the intersection of the draftThe necessary taper on the side of a forging to allow removal from the dies; also applies to the die impression. Commonly expressed in degrees as the draft angle. As applied to open die forging, draft is the amount of relative movement of the dies toward each other through the metal in one application of power.... More and flash at the body of the forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. to the trimmed edge of the stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging..

Flash land

Configuration in the blocking or finishing impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. of forging diesForms for making forgings; they generally consist of a top and bottom die. The simplest will form a completed forging in a single impression; the most complex, consisting of several die inserts, may have a number of impressions for the progressive working of complicated shapes. Forging dies are usually in pairs, with part of the impression in one of the blocks and the rest of the impression in the other block.... More designed to restrict or to encourage the growth of flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More at the parting line(1) The line along the surface of a forging where the dies meet, usually at the largest cross section of the part. Flash is formed at the parting line. (2) The plane that divides the two forging die halves., whichever may be required in a particular case to ensure complete filling of the impression.

Flash line

The line left on a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. after the flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More has been trimmed off. See Parting Line(1) The line along the surface of a forging where the dies meet, usually at the largest cross section of the part. Flash is formed at the parting line. (2) The plane that divides the two forging die halves..

Flash, internal

That portion of the flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More located entirely within a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. or enclosed by two or more forgings within a cluster of forgings.

Flashless forging

“True” closed die forgingThe shaping of hot metal completely within the walls or cavities of two dies that come together to enclose the workpiece on all sides. The impression for the forging can be entirely in either die or divided between the top and bottom dies. Impression-die forging, often used interchangeably with the term closed-die forging, refers to a closed-die operation in which the dies contain a provision for controlling the flow of excess material, or flash, that is generated. By contrast, in flashless forging, the material is deformed in a cavity that allows little or no escape of excess material. See Impression Die Forging.... More in which metal deformed in a dieThe machined recess in a die that gives the forging its shape. cavityThe machined recess in a die that gives the forging its shape. permits virtually no excess metal to escape.

Flat die forging (open die forging)

ForgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. worked between flat or simple contour diesThe metal blocks into which forging impressions are machined and from which forgings are produced. by repeated strokes and manipulation of the workpiece. Also known as “hand” or “smith” forging. See Open-Die Forging.

Flattener

Usually a flat surface cut to an exact depth below the parting line(1) The line along the surface of a forging where the dies meet, usually at the largest cross section of the part. Flash is formed at the parting line. (2) The plane that divides the two forging die halves. in each dieThe machined recess in a die that gives the forging its shape. to widen the material so as to more nearly cover the next impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging..

Flattening

The forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. operation of flatteningThe forging operation of flattening the forging stock prior to further working. the forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging. prior to further working.

Floating die

(1) A dieThe machined recess in a die that gives the forging its shape. mounted in a die holderA block used as an adapter in order to permit the use of forging dies that otherwise would not have sufficient height to be used in the particular unit or to permit the use of dies in a unit where the shank sizes are different. or a punch mounted in its holder such that a slight amount of motion compensates for toleranceThe permissible deviation from a specification for any design characteristic. in the dieThe machined recess in a die that gives the forging its shape. parts, the work, or the pressA machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface; the ram is guided in the frame of the machine.. (2) A die mounted on heavy springs to allow vertical motion in some trimming, shearing, and forming operations.

Flow lines

Patterns in a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. resulting from the elongation of nonhomogeneous constituents and the grainAn individual crystal in a polycrystalline metal or alloy. structure of the material in the direction of working during forging; usually revealed by macroetching. See also Grain FlowFiber-like lines appearing on polished and etched sections of forgings that are caused by orientation of the constituents of the metal in the direction of working during forging. Grain flow produced by proper die design can improves the mechanical properties of forgings.... More.

Flow stress

A measure of materials resistance to deformation and depends upon such things as temperatureThe temperature of the forging stock just prior to forging. and strain rateThe rate at which metal is deformed..

Flow-through

A forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. defect caused by metal flow past the base of a ribA relatively flat (but generally with draft) thin portion of a forging, generally perpendicular to the forging plane. with consequent rupture of the grainAn individual crystal in a polycrystalline metal or alloy. structure.

Fluorescent magnetic particle inspection

Inspection with either dry magnetic particles or those in a liquid suspension, the particles being coated with a fluorescent substance to increase the visibility of the indications.

Fold

A forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. defect caused by folding the metal back on its own surface during its flow in the dieThe machined recess in a die that gives the forging its shape. cavityThe machined recess in a die that gives the forging its shape.. See LapA surface irregularity appearing as a fissure or opening, caused by the folding over of hot metal, fins or sharp corners and by subsequent rolling or forging (but not welding) of these into the surface..

Force multiplier

A dimensionless factor that is used to describe the relative force requirement of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. or a forging section.

Forgeability

The relative ability of material to deform without fracturing, rupturing, or developing flaws. Also describes the resistance to flow from deformation. See also Formability.

Forging

The process of working metal to a desired shape by impact or pressure in hammers, forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. machines (upsetters), presses, rolls, and related forming equipment.

Forging billet

A wrought metal slug(1) Forging stock for one workpiece cut to length. See also Blank. (2) Metal removed when punching a hole in a forging (also termed "punchout"). used as forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging..

Forging dies

Forms for making forgings; they generally consist of a top and bottom dieThe machined recess in a die that gives the forging its shape.. The simplest will form a completed forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. in a single impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging.; the most complex, consisting of several dieThe machined recess in a die that gives the forging its shape. inserts, may have a number of impressions for the progressive working of complicated shapes. Forging diesForms for making forgings; they generally consist of a top and bottom die. The simplest will form a completed forging in a single impression; the most complex, consisting of several die inserts, may have a number of impressions for the progressive working of complicated shapes. Forging dies are usually in pairs, with part of the impression in one of the blocks and the rest of the impression in the other block.... More are usually in pairs, with part of the impression in one of the blocks and the rest of the impression in the other blockThe forging operation in which metal is progressively formed to general desired shape and contour by means of an impression die (used when only one block operation is scheduled)..

Forging envelope

See Finish AllowanceThe amount of stock left on the surface of the forging to be removed by subsequent machining. Also called "machining allowance" or "forging envelope.".

Forging machine (upsetter or header)

A type of forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. equipment, related to the mechanical pressA forging press with an inertia flywheel, a crank and clutch, or other mechanical device to operate the ram., in which the main forming energy is applied horizontally to the workpiece, which is gripped and held by prior action of the grip diesThe metal blocks into which forging impressions are machined and from which forgings are produced..

Forging plane

The plane that includes the principal dieThe machined recess in a die that gives the forging its shape. face and is perpendicular to the direction of ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. travel. When parting surfaces of the diesThe metal blocks into which forging impressions are machined and from which forgings are produced. are flat, the forging planeThe plane that includes the principal die face and is perpendicular to the direction of ram travel. When parting surfaces of the dies are flat, the forging plane coincides with the parting line. coincides with the parting line(1) The line along the surface of a forging where the dies meet, usually at the largest cross section of the part. Flash is formed at the parting line. (2) The plane that divides the two forging die halves..

Forging quality

Term describing stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. of sufficiently superior quality to make it suitable for commercially satisfactory forgings.

Forging reduction

Ratio of the cross-sectional areas before and after forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment.; sometimes refers to percentage reduction in thickness.

Forging roll

Also known as reducer roll. A machine situated alongside the forging machineA type of forging equipment, related to the mechanical press, in which the main forming energy is applied horizontally to the workpiece, which is gripped and held by prior action of the grip dies. for pre-forming. The operation is carried out by passing the work-piece between contra-rotating shafts, which carry appropriately shaped diesThe metal blocks into which forging impressions are machined and from which forgings are produced..

Forging stock

A wrought rod, barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More, or other section suitable for subsequent change in cross section by forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment..

Forging stresses

Elastic residual stresses induced by forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. or by cooling from the forging temperatureThe temperature of the forging stock just prior to forging.. They can be relieved by subsequent annealing or normalizing.

Form rolling

Hot rolling to produce bars having contoured cross sections; not to be confused with the roll forming of sheet metal or with roll forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment..

Forward extrusion

Same as direct extrusionSee Extrusion.. See ExtrusionThe process of forcing metal to flow through a die orifice in the same direction in which energy is being applied (forward extrusion); or in the reverse direction (backward extrusion), in which case the metal usually follows the contour of the punch or moving forming tool. The extrusion principle is used in many impression die forging applications.... More.

Fracture toughness

The resistance of a given material to catastrophic failure in the presence of an existing sharp crack.

Frame

The main structure of a pressA machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface; the ram is guided in the frame of the machine..

Friction factor

A factor that, when multiplied by the flow stressA measure of materials resistance to deformation and depends upon such things as temperature and strain rate., expresses the friction shear stress.

Fuller (fullering impression)

Portion of the dieThe machined recess in a die that gives the forging its shape. that is used in hammer forgingThe mechanical forming of metal by means of a hammer. The action of the hammer is that of an instantaneous application of pressure in the form of a sudden blow. primarily to reduce the cross section and lengthen a portion of the forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging.. The fullering impressionPortion of the die that is used in hammer forging primarily to reduce the cross section and lengthen a portion of the forging stock. The fullering impression is often used in conjunction with an edger (or edging impression). is often used in conjunction with an edgerThe portion of the die impression that distributes metal, during forging, into areas where it is most needed to facilitate filling the cavities of subsequent impressions to be used in the forging sequence. See also Fuller. (or edging impressionThe portion of the die impression that distributes metal, during forging, into areas where it is most needed to facilitate filling the cavities of subsequent impressions to be used in the forging sequence. See also Fuller.).

Fullering

Reducing the cross section of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. between ends of stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging..

Gate (sprue)

A portion of the dieThe machined recess in a die that gives the forging its shape. that has been removed by machining and permits the barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More or tongsMetal holder used to handle hot or cold forgings. to be closer to the impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. without being smashed.

Gathering stock

Any operation whereby the cross-section of a portion of the forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging. is increased above its original size.

Gibs

Guides or shoes that ensure the proper parallelism, squareness, and sliding fit between pressA machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface; the ram is guided in the frame of the machine. components such as the ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. and the frameThe main structure of a press.. They are usually adjustable to compensate for wear and to establish operating clearance.

Grain

An individual crystal in a polycrystalline metal or alloy.

Grain flow

Fiber-like lines appearing on polished and etched sections of forgings that are caused by orientation of the constituents of the metal in the direction of working during forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment.. Grain flowFiber-like lines appearing on polished and etched sections of forgings that are caused by orientation of the constituents of the metal in the direction of working during forging. Grain flow produced by proper die design can improves the mechanical properties of forgings.... More produced by proper dieThe machined recess in a die that gives the forging its shape. design can improves the mechanical properties of forgings.

Grain growth

An increase in the size of the grains of a metal with a proportional reduction of the number of grains.

Grain separation

In forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. aluminum, rapid metal flow sometimes causes a separation or rupture of grainAn individual crystal in a polycrystalline metal or alloy.. Metal flow is affected by lubricantA material applied to dies, molds, plungers, or workpieces that promotes the flow of metal, reduces friction and wear, and aids in the release of the finished part., dieThe machined recess in a die that gives the forging its shape. and metal temperatureThe temperature of the forging stock just prior to forging., part shape, alloy, and hammerA machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer. operator technique; consequently, any one or combination of these factors can cause grain separationIn forging aluminum, rapid metal flow sometimes causes a separation or rupture of grain. Metal flow is affected by lubricant, die and metal temperature, part shape, alloy, and hammer operator technique; consequently, any one or combination of these factors can cause grain separation. The irregular crevices are seldom more than a few thousandths of an inch deep and can be removed by grinding or polishing.... More. The irregular crevices are seldom more than a few thousandths of an inch deep and can be removed by grinding or polishing.

Grain size

An expression that rates the number of grains per unit area of cross section as determined by metallographic examination.

Gravity hammer

A class of forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. hammerA machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer. wherein energy for forging is obtained by the mass and velocity of a freely falling ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. and the attached upper dieThe machined recess in a die that gives the forging its shape.. Examples are board hammers and air-lift hammers.

Gripper dies

The lateral or clamping diesThe metal blocks into which forging impressions are machined and from which forgings are produced. used in a mechanical upsetterA three-element forging press, with two gripper dies and a forming tool, for flanging or forming relatively deep recesses. or forging machineA type of forging equipment, related to the mechanical press, in which the main forming energy is applied horizontally to the workpiece, which is gripped and held by prior action of the grip dies..

Guide

The parts of a drop hammerA term generally applied to forging hammers wherein energy for forging is provided by gravity, steam, or compressed air. See also Air-Lift Hammer, Board Hammer, Steam Hammer. or pressA machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface; the ram is guided in the frame of the machine. that guideThe parts of a drop hammer or press that guide the up-and-down motion of the ram in a true vertical direction. the up-and-down motion of the ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. in a true vertical direction.

Gutter

A shallow impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. machined around the periphery of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. die impressionThe portion of the die surface that shapes the forging. outside the flash landConfiguration in the blocking or finishing impression of forging dies designed to restrict or to encourage the growth of flash at the parting line, whichever may be required in a particular case to ensure complete filling of the impression. that acts as a reservoir for excess metal.

Hammer

A machine that applies a sharp blow to the work area through the fall of a ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. onto an anvil. The ram can be driven by gravity or power. See also Gravity HammerA class of forging hammer wherein energy for forging is obtained by the mass and velocity of a freely falling ram and the attached upper die. Examples are board hammers and air-lift hammers. and Power-Driven HammerA forging hammer with a steam or air cylinder for raising the ram and augmenting its downward blow..

Hammer forging

The mechanical forming of metal by means of a hammerA machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer.. The action of the hammer is that of an instantaneous application of pressure in the form of a sudden blow.

Hand forging

(See also Open Die ForgingForging worked between flat or simple contour dies by repeated strokes and manipulation of the workpiece. Also known as "hand" or "smith" forging. See Open-Die Forging.) (1) A forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. made by hand on an anvil or under a power hammerA machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer. without diesThe metal blocks into which forging impressions are machined and from which forgings are produced. containing an exact finishing impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. of the part. Such forgings approximate each other in size and shape but do not have the commercial exactness of production dieThe machined recess in a die that gives the forging its shape. forgings. Used where the quantity of forgings required does not warrant expenditure for special diesThe metal blocks into which forging impressions are machined and from which forgings are produced., or where the size or shape of the piece is such as to require means other than dieThe machined recess in a die that gives the forging its shape. forging. (2) A forging worked between flat or simply shaped dies by repeated strokes and manipulation of the piece. Also known as smith forgingSee Flat die forging, Hand forging. or flat die forgingForging worked between flat or simple contour dies by repeated strokes and manipulation of the workpiece. Also known as "hand" or "smith" forging. See Open-Die Forging..

Hand straightening

A straightening operation performed on a surface plate to bring a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. within the straightness toleranceThe permissible deviation from a specification for any design characteristic.. Frequently, a bottom dieThe machined recess in a die that gives the forging its shape. from a set of finish(1) The forging operation in which the part is forged into its final shape in the finish die. If only one finish operation is scheduled to be performed in the finish die, this operation will be identified simply as finish; first, second, or third finish designations are so termed when one or more finish operations are to be performed in the same finish die. (2) The surface condition of a forging after machining. (3) The material machined off the surface of a forging to produce the finish machine component.... More diesThe metal blocks into which forging impressions are machined and from which forgings are produced. is used instead of a surface plate. Hand tools used include mallets, sledges, blocks, jacks, and oil gear presses in addition to regular inspection tools.

Handling hole

Holes drilled in opposite ends of the dieThe machined recess in a die that gives the forging its shape. blockThe forging operation in which metal is progressively formed to general desired shape and contour by means of an impression die (used when only one block operation is scheduled). to permit handling by the use of a crane or barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More.

Handling marks

Nicks and gouges formed on forgings if improperly handled; most prevalent for forgings in the as-forged condition prior to heat treatmentA sequence of controlled heating and cooling operations applied to a solid metal to impart desired properties..

Header

See Forging machineA type of forging equipment, related to the mechanical press, in which the main forming energy is applied horizontally to the workpiece, which is gripped and held by prior action of the grip dies..

Heading

The upsetting of wire, rod, or barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. in diesThe metal blocks into which forging impressions are machined and from which forgings are produced. to form parts that usually contain portions that are greater in cross-sectional area than the original wire, rod, or bar.

Heat

A term used to identify the material produced from a single melting operation. Different heats of the same material can vary in chemical composition within prescribed limits. StockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. from a single heatAmount of forging stock placed in a batch-type furnace at one time. will have a consistent analysis and more uniform properties. Also known in the U.K. as “Cast”.

Heat (forging)

Amount of forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging. placed in a batch-type furnace at one time.

Heat analysis

See Ladle analysisThe results of the chemical analysis of a test sample taken during the pouring of a melt. Also called heat analysis..

Heat treatment

A sequence of controlled heating and cooling operations applied to a solid metal to impart desired properties.

Hogout

A product machined from barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More or plate stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging. or from a hand forging(See also Open Die Forging) (1) A forging made by hand on an anvil or under a power hammer without dies containing an exact finishing impression of the part. Such forgings approximate each other in size and shape but do not have the commercial exactness of production die forgings. Used where the quantity of forgings required does not warrant expenditure for special dies, or where the size or shape of the piece is such as to require means other than die forging. (2) A forging worked between flat or simply shaped dies by repeated strokes and manipulation of the piece. Also known as smith forging or flat die forging.... More, rather than from an impression die forgingA forging that is formed to the required shape and size by machined impressions in specially prepared dies that exert three-dimensional control on the workpiece.. The process is commonly known as “hogging out” material.

Hollow forging

(1) Processes for forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. tubes or ring forgings. (2) Cylindrical open die forgingForging worked between flat or simple contour dies by repeated strokes and manipulation of the workpiece. Also known as "hand" or "smith" forging. See Open-Die Forging., e.g., thick-walled tubes or rings.

Hot forging

Same as hot working—plastically deforming an alloy at a temperatureThe temperature of the forging stock just prior to forging. above its recrystallization point, i.e, high enough to avoid strain hardeningAn increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening..

Hot inspection

An in-process examination of forgings, using gauges, templates, or other nondestructive inspectionAny method of detection or measurement of the properties or performance capabilities of materials, parts, assemblies, or structures that does not impair the surface or internal integrity of the part. methods to ensure quality.

Hot shortness

Lack of ductilityThe property of a metal that enables it to stretch before rupturing. when metal is hot.

Hot trimming

The removal of flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More or excess metal from a hot part (such as a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment.) in a trimming pressA power press suitable for trimming flash from forgings..

Hot upset forging

A bulk forming process for enlarging and reshaping some of the cross-sectional area of a barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More, tube, or other product form of uniform (usually round) section. It is accomplished by holding the heated forging stockA wrought rod, bar, or other section suitable for subsequent change in cross section by forging. between grooved diesThe metal blocks into which forging impressions are machined and from which forgings are produced. and applying pressure to the end of the stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging., in the direction of its axis, by the use of a headingThe upsetting of wire, rod, or bar stock in dies to form parts that usually contain portions that are greater in cross-sectional area than the original wire, rod, or bar. tool, which spreads (upsets) the end by metal displacement. Also called hot heading or hot upsetting. See also Heading and Upsetting.

Hot working

The plastic deformation of metal at such a temperatureThe temperature of the forging stock just prior to forging. and strain rateThe rate at which metal is deformed. that recrystallization takes place simultaneously with the deformation, thus avoiding any strain hardeningAn increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening.. Also referred to as hot forgingSame as hot working—plastically deforming an alloy at a temperature above its recrystallization point, i.e, high enough to avoid strain hardening. and hot forming. Contrast with cold workingPermanent plastic deformation of a metal at a temperature below its recrystallization point—low enough to produce strain hardening. Usually, but not necessarily, conducted at room temperature. Also referred to as cold forming or cold forging. Contrast with hot working.... More.

Hot-die forging

A process in which diesThe metal blocks into which forging impressions are machined and from which forgings are produced. are heated close to the forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. temperatureThe temperature of the forging stock just prior to forging. of the alloy being forged; used for difficult-to-forge alloys.

Hub

A bossA relatively short protrusion or projection on the surface of a forging, often cylindrical in shape. that is in the center of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. and forms a part of the body of the forging.

Hydraulic hammer

A gravity-drop forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. hammerA machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer. that uses hydraulic pressure to lift the hammer between strokes.

Hydraulic press

A forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. pressA machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface; the ram is guided in the frame of the machine. with a hydraulically operated ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened..

Impact extrusion

A reverse extrusionThe process of forcing metal to flow through a die orifice in the same direction in which energy is being applied (forward extrusion); or in the reverse direction (backward extrusion), in which case the metal usually follows the contour of the punch or moving forming tool. The extrusion principle is used in many impression die forging applications.... More process in which metal is displaced backwards between a punch and a dieThe machined recess in a die that gives the forging its shape. to form a hollow part.

Impact test

Test to determine the energy absorbed in fracturing a notched test barA section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges, with a cross-sectional area of less than 16 sq in. (A solid section that is long in relation to its cross-sectional dimensions, having a completely symmetrical cross section and whose width or greatest distance between parallel faces is 3/8 in. or more).... More at high velocity. See also Charpy Test, Izod Test.

Impact velocity

The relative velocity of the forging diesForms for making forgings; they generally consist of a top and bottom die. The simplest will form a completed forging in a single impression; the most complex, consisting of several die inserts, may have a number of impressions for the progressive working of complicated shapes. Forging dies are usually in pairs, with part of the impression in one of the blocks and the rest of the impression in the other block.... More just prior to impact.

Impression

A cavityThe machined recess in a die that gives the forging its shape., or series of cavities (multiple(1) Term used to describe a die impression designed to produce more than a single piece at a time. (2) A piece of stock for forging that is cut from bar or billet lengths to provide the exact amount of material needed for a single workpiece.), machined into a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. dieThe machined recess in a die that gives the forging its shape. to produce a desired configuration in the workpiece during forging.

Impression die forging

A forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. that is formed to the required shape and size by machined impressions in specially prepared diesThe metal blocks into which forging impressions are machined and from which forgings are produced. that exert three-dimensional control on the workpiece.

Inclusions

Particles of nonmetallic compounds of metals and impurity elements that are present in ingots and are carried over in wrought products. The shape and distribution of inclusionsParticles of nonmetallic compounds of metals and impurity elements that are present in ingots and are carried over in wrought products. The shape and distribution of inclusions are changed by plastic deformation and contribute to directionality in metals.... More are changed by plastic deformation and contribute to directionality in metals.

Indirect (backward) extrusion

See ExtrusionThe process of forcing metal to flow through a die orifice in the same direction in which energy is being applied (forward extrusion); or in the reverse direction (backward extrusion), in which case the metal usually follows the contour of the punch or moving forming tool. The extrusion principle is used in many impression die forging applications.... More.

Ingot

A casting intended for subsequent rolling, forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment., or extrusionThe process of forcing metal to flow through a die orifice in the same direction in which energy is being applied (forward extrusion); or in the reverse direction (backward extrusion), in which case the metal usually follows the contour of the punch or moving forming tool. The extrusion principle is used in many impression die forging applications.... More.

Ingotism

A term used to describe the remnants of dendritic structure which may occasionally be found in forgings.

Insert

A piece of steel that is tightly fixed in a dieThe machined recess in a die that gives the forging its shape.. The insertA piece of steel that is tightly fixed in a die. The insert may be used to fill a cavity, to replace a portion of the die with a grade of steel that is better suited for service at that point, or to function as a small die with the impression fastened to a master die.... More may be used to fill a cavityThe machined recess in a die that gives the forging its shape., to replace a portion of the dieThe machined recess in a die that gives the forging its shape. with a grade of steel that is better suited for service at that point, or to function as a small die with the impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. fastened to a masterWood, metal or plastic reproduction of a proposed forged shape, used to control cutters on tracer-controlled die sinking equipment. die.

Insert die

A relatively small dieThe machined recess in a die that gives the forging its shape. containing part or all of the impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment., and which is fitted to the masterWood, metal or plastic reproduction of a proposed forged shape, used to control cutters on tracer-controlled die sinking equipment. dieThe machined recess in a die that gives the forging its shape. blockThe forging operation in which metal is progressively formed to general desired shape and contour by means of an impression die (used when only one block operation is scheduled). by means of a key.

Isothermal forging

A hot-forging process in which a constant and uniform temperatureThe temperature of the forging stock just prior to forging. is maintained in the workpiece during forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. by heating the diesThe metal blocks into which forging impressions are machined and from which forgings are produced. to the same temperatureThe temperature of the forging stock just prior to forging. as the workpiece. Most commonly conducted at about 2000°F under a controlled atmosphere or in a vacuum to prevent oxidation while forging superalloysA term broadly applied to iron-base, nickel-base, and cobalt-base alloys, often quite complex, that exhibit high elevated-temperature mechanical properties and oxidation resistance..

Izod impact test

A pendulum-type impact testTest to determine the energy absorbed in fracturing a notched test bar at high velocity. See also Charpy Test, Izod Test. in which the specimen is supported at one end as a cantilever beam and the energy required to break off the free end by the impact of a falling pendulum is used as a measure of impact strength. See Charpy Impact TestAn impact test in which a specially V-notched specimen is broken by the impact of a falling pendulum. The energy absorbed in fracture is a measure of the impact strength or notch toughness of the sample..

Knockout

A mechanism for releasing workpieces from a dieThe machined recess in a die that gives the forging its shape..

Knockout mark

A small protrusion, such as a button or ring of flashMetal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies. Flash extends out from the body of the forging as a thin plate at the line where the dies meet and is subsequently removed by trimming. Because it cools faster than the body of the component during forging, flash can serve to restrict metal flow at the line where dies meet, thus ensuring complete filling of the impression. See also Closed-Die Forging.... More, resulting from the depression of a knockout pinA power-operated plunger installed in a die to aid removal of the finished forging. from the forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. pressure, or the entrance of metal between the knockoutA mechanism for releasing workpieces from a die. pin and the dieThe machined recess in a die that gives the forging its shape..

Knockout pin

A power-operated plunger installed in a dieThe machined recess in a die that gives the forging its shape. to aid removal of the finished forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment..

Ladle analysis

The results of the chemical analysis of a test sample taken during the pouring of a melt. Also called heat analysisSee Ladle analysis..

Lap

A surface irregularity appearing as a fissure or opening, caused by the folding over of hot metal, fins or sharp corners and by subsequent rolling or forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. (but not welding) of these into the surface.

Layout

(1) Transferring drawing(1) A forging operation in which the cross section of forging stock is reduced and the stock lengthened between flat or simple contour dies. See also Fullering. (2) in heat treating, the same as tempering. or sketch dimensions to templates or diesThe metal blocks into which forging impressions are machined and from which forgings are produced. for use in sinkingThe operation of machining the impression of a desired forging into die blocks. diesThe metal blocks into which forging impressions are machined and from which forgings are produced.. (2) A detailed inspection operation in which significant dimensions of a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. are checked against blueprint specificationsThe Society of Automotive Engineers..

Layout sample

A plaster, lead, or forged alloy sample taken from new diesThe metal blocks into which forging impressions are machined and from which forgings are produced. to verify accuracy by layout(1) Transferring drawing or sketch dimensions to templates or dies for use in sinking dies. (2) A detailed inspection operation in which significant dimensions of a forging are checked against blueprint specifications. and precise measurement. See also CastAny reproduction of a die cavity in any material, frequently lead, plaster or epoxy, used to confirm the exactness of the cavity. See Die Proof..

Lead proof

A reproduction in lead, or a lead alloy, of the die impressionThe portion of the die surface that shapes the forging., obtained by clamping the two diesThe metal blocks into which forging impressions are machined and from which forgings are produced. together in alignment and pouring molten metal into the finish impressionThe die impression that imparts the final shape to a forged part..

Liftout

The mechanism also known as knockoutA mechanism for releasing workpieces from a die..

Lock

In forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment., a condition in which the flash lineThe line left on a forging after the flash has been trimmed off. See Parting Line. is not entirely in one plane. Where two or more plane changes occur, it is called compound lockIn forging, a condition in which the flash line is not entirely in one plane. Where two or more plane changes occur, it is called compound lock. Where a lock is placed in the die to compensate for die shift caused by a steep lock, it is called a counterlock.... More. Where a lock is placed in the dieThe machined recess in a die that gives the forging its shape. to compensate for die shiftThe condition that occurs after the dies have been set up in a forging unit in which a portion of the impression of one die is not in perfect alignment with the corresponding portion of the other die. This results in a mismatch in the forging, a condition that must be held within the specified tolerance.... More caused by a steep lock, it is called a counterlock.

Locked dies

DiesThe metal blocks into which forging impressions are machined and from which forgings are produced. with mating faces that lie in more than one plane.

Lower punch

The lower part of a dieThe machined recess in a die that gives the forging its shape., which forms the bottom of the dieThe machined recess in a die that gives the forging its shape. cavityThe machined recess in a die that gives the forging its shape. and which may or may not move in relation to the die body; usually movable in a forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. die.

Lubricant

A material applied to diesThe metal blocks into which forging impressions are machined and from which forgings are produced., molds, plungers, or workpieces that promotes the flow of metal, reduces friction and wear, and aids in the release of the finished part.

Lubricant residue

The carbonaceous residue resulting from lubricantA material applied to dies, molds, plungers, or workpieces that promotes the flow of metal, reduces friction and wear, and aids in the release of the finished part. burned on the surface of a hot forged part.