Glossary

T-Z

Table mill

In ring rolling, a type of ring 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 employing 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. mandrels with a common main roll. Usually used in high volume production of small-diameter rolled rings.

Target machining

Incorporating a “target” (benchmark or gage point) 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. to facilitate machining; coined locating surfaces and drilled centers are commonly used.

Temperature (Forging)

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

Template (Templet)

A gage or pattern made in a dieThe machined recess in a die that gives the forging its shape. department, usually from sheet steel; used to checkCrack in a die impression, generally due to forging pressure and/or excessive die temperature. Die blocks too hard for the depth of the die impression have a tendency to check or develop cracks in impression corners. dimensions on forgings and as an aid in sinkingThe operation of machining the impression of a desired forging into die blocks. dieThe machined recess in a die that gives the forging its shape. impressions in order to correct dimensions.

Thermal cracks

Ruptures in metal set up by stresses due to thermal differentials.

Thermal stress

Stresses in metal resulting from non-uniform distribution of heatAmount of forging stock placed in a batch-type furnace at one time..

Thermomechanical working

A general term covering a variety of processes combining controlled thermal and deformation treatments to obtain synergistic effects, such as improvement in strength without loss of toughness.

Tolerance

The permissible deviation from a specification for any design characteristic.

Tong hold

The portion of the forging billetA wrought metal slug used as forging stock., usually on one end, that is gripped by the operator’s tongsMetal holder used to handle hot or cold forgings.. It is removed from the part at the end 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. operation. Common to 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. and press-type forging.

Tongs

Metal holder used to handle hot or coldFaults produced in a forging by incorrect tool design or incorrect flow of steel that results in the formation of a crack in the forging surface. forgings.

Tool steel

A superior grade of steel made primarily for use in tools and diesThe metal blocks into which forging impressions are machined and from which forgings are produced..

Tooling marks

Indications imparted to the surface of the forged part from diesThe metal blocks into which forging impressions are machined and from which forgings are produced. containing surface imperfections or diesThe metal blocks into which forging impressions are machined and from which forgings are produced. on which some repair work has been done. These marks are usually slight rises or depressions in the metal.

Tooling pad

See Chucking lugA lug or boss to the forging so that "on center" machining and forming can be performed with one setting or chucking; this lug is machined or cut away on the finished item..

Trepanning

Removal of a core of metal by a hollow tool. May be performed by a hollow punch at forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. temperatures or by a hollow cutting tool by machining at ambient temperatures.

Trim

The removal of the excess metal or 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 produced during 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. process. The operation takes place in tools produced to the peripheral shape of the component, the component being pushed through the female impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. by the identically-shaped male punch. The operation may be carried out hot or at room temperatureThe temperature of the forging stock just prior to forging..

Trim and punch

(1) A shearing operation to remove both an inner and an outer section of metal from a blocked or 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.. (2) A combination of two operations whereby 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 and punchoutMetal removed when punching a hole in a forging. are removed simultaneously. The operation is generally performed on a trimThe removal of the excess metal or flash produced during the forging process. The operation takes place in tools produced to the peripheral shape of the component, the component being pushed through the female impression by the identically-shaped male punch. The operation may be carried out hot or at room temperature.... More 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. using a combination trim and punch(1) A shearing operation to remove both an inner and an outer section of metal from a blocked or finished forging. (2) A combination of two operations whereby flash and punchout are removed simultaneously. The operation is generally performed on a trim press using a combination trim and punch die.... More dieThe machined recess in a die that gives the forging its shape..

Trimmer

The combination of trimmerThe combination of trimmer punch, trimmer blades, and perhaps trimmer shoe used to remove flash from a forging. punch, trimmer blades, and perhaps trimmer shoeA holder used as a support for the stationary portions of forging and trimming dies. used to remove 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 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..

Trimmer blade

The portion of the trimmers through which 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. is pushed to shear off 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. The shearing edge may be in more than one plane in order to fit 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. of the forging.

Trimmer die

The upper portion of the trimmerThe combination of trimmer punch, trimmer blades, and perhaps trimmer shoe used to remove flash from a forging. that comes in contact with 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. and pushes it through the trimmer blades; the lower end of the trimmer punch is generally shaped to fit the surface of the forging against which it pushes. Also termed Trimmer punch.

Trimming press

A power 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. suitable for trimming 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 from forgings.

Tryout

Preparatory run to checkCrack in a die impression, generally due to forging pressure and/or excessive die temperature. Die blocks too hard for the depth of the die impression have a tendency to check or develop cracks in impression corners. or test equipment, 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., stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging., tools, or methods prior to a production run. Production tryoutPreparatory run to check or test equipment, lubricant, stock, tools, or methods prior to a production run. Production tryout is run with tools previously approved; new die tryout is run with new tools not previously approved. is run with tools previously approved; new dieThe machined recess in a die that gives the forging its shape. tryout is run with new tools not previously approved.

Tumbling

(1) The process for removing scale from forgings in a rotating container by means of impact with each other and abrasive particles and small bits of metal. (2) A process for removing scale and roughness from forgings by impact with each other, together with abrasive material in a rotating container.

Turning

Removing metal from the outside of a part by means of a tool in a lathe or similar machine tool.

Ultrasonic testing

A method of nondestructive testingA nondestructive method of inspection/testing for determining the existence and extent of possible defects in ferro-magnetic materials. The metal is magnetized, then iron powder is applied. The powder adheres to lines of flux leakage, revealing surface and near-surface discontinuities.... More of solid metal for internal flaws utilizing high-frequency sound waves.

Undercuts

Sections 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. which, if driven into the impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. while the metal is hot, would 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 themselves into a die impressionThe portion of the die surface that shapes the forging. and prevent removal of the forging without distortion.

Underfill

A portion 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. that has insufficient metal to give it the true shape of the impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging..

UNS

The Unified Numbering System. A system that provides a means of correlating many nationally used numbering systems currently administered by societies, trade associations, and individual users and producers of metals and alloys, thereby avoiding confusion caused by use of more than one identification number for the same material. It also avoids having the same number assigned to two or more entirely different materials.

Upset 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 upsetting an appropriate length of 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, billetA semifinished, cogged, hot-rolled, or continuous-cast metal product of uniform section, usually rectangular with radiused corners. Billets are relatively larger than bars. See Bloom. or bloomA semifinished product of square, rectangular, or even round cross section, hot rolled, or forged. For steel, the width of a bloom is not more than twice the thickness, and the cross sectional area is usually not less than about 36 sq. in. No invariable rule prevails for distinguishing between blooms and billets; the terms are frequently used interchangeably.... More. (2) Working metal to increase the cross-sectional area of a portion or all of the stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging.. (3) A forging formed by 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. or gathering the material by pressure upon hot or coldFaults produced in a forging by incorrect tool design or incorrect flow of steel that results in the formation of a crack in the forging surface. metal between diesThe metal blocks into which forging impressions are machined and from which forgings are produced. operated in a horizontal plane.

Upsetter (Forging machine)

A horizontal 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. where the workpiece is gripped between two grooved diesThe metal blocks into which forging impressions are machined and from which forgings are produced. and deformed by a punch that exerts force on the end of the stockThe material to be forged regardless of form. Also, an individual piece of metal used to produce a single forging..

Vent

A small hole in a punch or dieThe machined recess in a die that gives the forging its shape. for admitting air to avoid suction holding or for relieving pockets of trapped air that would prevent dieThe machined recess in a die that gives the forging its shape. closure or action.

Vent mark

A small protrusion resulting from the entrance of metal into dieThe machined recess in a die that gives the forging its shape. ventA small hole in a punch or die for admitting air to avoid suction holding or for relieving pockets of trapped air that would prevent die closure or action. holes.

Warm forging

Deformation at elevated temperatures below the recrystallization temperatureThe temperature of the forging stock just prior to forging.. The flow stressA measure of materials resistance to deformation and depends upon such things as temperature and strain rate. and rate of strain hardeningAn increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening. are reduced with increasing temperatureThe temperature of the forging stock just prior to forging.; thus, lower forces are required than in 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. For steel, the temperatures range from about 1000° F to just below the normal hot workingThe plastic deformation of metal at such a temperature and strain rate that recrystallization takes place simultaneously with the deformation, thus avoiding any strain hardening. Also referred to as hot forging and hot forming. Contrast with cold working.... More range of 1900 to 2300° F. See also ColdFaults produced in a forging by incorrect tool design or incorrect flow of steel that results in the formation of a crack in the forging surface. Working and Hot Working.

Warpage

Term generally applied to distortion that results during quenching from heat-treating temperatures; hand straighteningA straightening operation performed on a surface plate to bring a forging within the straightness tolerance. Frequently, a bottom die from a set of finish dies 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.... More, 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. straightening, or coldFaults produced in a forging by incorrect tool design or incorrect flow of steel that results in the formation of a crack in the forging surface. restriking is employed, depending on the configuration of the part and the amount of warpageTerm generally applied to distortion that results during quenching from heat-treating temperatures; hand straightening, press straightening, or cold restriking is employed, depending on the configuration of the part and the amount of warpage involved. The condition is governed by applicable straightness tolerances; beyond tolerances, warpage is defect and cause for rejection. The term is not to be confused with "bend" or "twist."... More involved. The condition is governed by applicable straightness tolerances; beyond tolerances, warpage is defect and cause for rejection. The term is not to be confused with “bend” or “twist.”

Ways

The fitted V-shaped grooves in the ramThe main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. and columns 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. 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 descent and ascent of the ram.

Web

A relatively flat, thin portion 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., generally parallel to the forging plane—that connects ribs and bosses. See also RibA relatively flat (but generally with draft) thin portion of a forging, generally perpendicular to the forging plane..

Wrought steel

A descriptive term for any particle of steel that has been produced by hot mechanical working.