Engineering Definitions

The female part of a complete die assembly. Usually the tool which “holds water” or is generally concave in geometric shape.

A dwell type cam-slide that generally fits the part shape and retracts to permit loading and unloading of the part. Also called fill slide.

Source: The OHIO State University

The concave intersection of two surfaces. In forging, the desired radius at the concave intersection of two surfaces is usually specified.

Source: The OHIO State University

Angle between a line (formed by a point on the final hem steel at first contact with flange to the same point at end of final hem) and the mating surface.

Source: The OHIO State University

Duration of time with which the final hem steel stays at the final hem position.

Source: The OHIO State University

Angle of the final hem steels measured relative to the mating flange area

Source: The OHIO State University

Maximum force required to bend flange from pre hem position to final hem position.

Source: The OHIO State University

Elastic recovery that follows plastic deformation when the final hem load is removed

Source: The OHIO State University

Hardened steels mounted to the hemmer to bend the flange from pre-hem angle to final hem.

Source: The OHIO State University

(1) The surface appearance of a product. (2) 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.

Source: The OHIO State University

The act of forming a panel shape to the finish position. Also see restrike.

Source: The OHIO State University

A method of analysis developed for prediction, practical forming of the instantaneous velocities, strain rates, strains, stresses and temperatures within the deforming metal.

Source: The OHIO State University

A projecting rim or edge of a part, usually narrow and of approximately constant width for stiffening or fastening.

Source: The OHIO State University

Die used to form a flange from a blank

Source: The OHIO State University

Inside of metal radius of the upturned flange of the outer panel formed by the flanging process over the flange die corner radius.

Source: The OHIO State University

Midpoint of the inside of metal breakline radius.

Source: The OHIO State University

Outside of metal radius of the upturned flange of the outer panel formed by the flanging process. It is equivalent to the sum of the inside breakline radius and the sheet metal thickness.

Source: The OHIO State University

Midpoint of the outside of metal breakline radius

Source: The OHIO State University

Flange material that has been cut to allow flange to lay flat after final hem.

Source: The OHIO State University

A steel used in a forming operation in which a narrow strip at the edge of a sheet or part is bent down along a straight or curved line. Also called a wiping steel.

Source: The OHIO State University

A stripper that pushes against the bottom edge or surface of a flange to release the part from the stool.

Source: The OHIO State University

(1) The process of forming or folding the edge of sheet metal part, to form an angled edge (often at 90 degrees) to the main sheet metal body.

(2) A bending operation in which a narrow strip at the edge of a sheet is bent up or down along a straight or curved line. It is used for edge strengthening, appearance, rigidity and the removal of sheared edges. A flange is often used as a fastening surface.

Source: The OHIO State University

Elastic recovery that follows plastic deformation when the flanging load is removed.

Source: The OHIO State University

(1) The excess metal attached to a part after a forming operation. (2) The excess material that squeezes out between the joint lines of mold dies.

Source: The OHIO State University

A flange that is folded back over upon itself. It is used primarily for appearance and removal of dangerous sheared edges. Also called closed hem.

Source: The OHIO State University

The removal of irregularities or distortion in sheets or plates by a method such as roller leveling or stretcher leveling.

Source: The OHIO State University

Dies used to flatten sheet metal hems; that is, dies that can flatten a bend by closing it. These dies consist of a top and bottom die with a flat surface that can close one section (flange) to another (hem, seam).

Source: The OHIO State University

A movable roll designed to push up against a sheet as it passes through a roller leveler. The flex roll can be adjusted to deflect the sheet any amount up to the roll diameter.

Source: The OHIO State University

Passing sheets through a flex roll unit to minimize yield-point elongation in order to reduce the tendency for stretcher strains to appear during forming.

Source: The OHIO State University

(1) A die mounted in a die holder or a punch mounted in its holder such that a slight amount of motion compensates for tolerance in the die parts, the work, or the press. (2) A die mounted on heavy springs to allow vertical motion in some trimming, shearing, and forming operations.

Source: the OHIO State University

A draw die punch that is supported by air cylinders or other means instead of being tied to the inner press ram. This allows adjustment for the amount of preform desired and helps to eliminate binding between the punch and the die.

Source: The OHIO State University

(1) Texture showing the direction of metal flow during hot or cold working. Flow lines can often be revealed by etching the surface or a section of a metal part. (2) In mechanical metallurgy, paths followed by minute volumes of metal during deformation.

Source: The OHIO State University

A modification of the Guerin process for forming sheet metal, the fluid-cell process uses higher pressure and is primarily designed for forming slightly deeper parts, using a rubber pad as either the die or punch. A flexible hydraulic fluid cell forces an auxiliary rubber pad to follow the contour of the form block and exert a nearly uniform pressure at all points on the workpiece. See also Jluid forming and rubber-pad forming.

Source: The OHIO State University

A modification of the Guerin process, fluid forming differs from the fluid-cell process in that the die cavity, called a pressure dome, is not completely filled with rubber, but with hydraulic fluid retained by a cup-shaped rubber diaphragm. See also rubber-padforming.

Source: The OHIO State University

The outer panel surface relationship to a mating panel

Source: The OHIO State University

A cutting die, saw, or wheel that cuts work to length while it is moving.

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A machine for cutting continuous rolled products to length that does not require a halt in rolling, but rather moves along the runout table at the same speed as the product while performing the cutting, and then returns to the starting point in time to cut the next piece.

Source: The OHIO State University

A progressive die consisting of two or more parts in a single holder; used with a separate lower die to perform more than one operation (such as piercing and blanking) on a part in two or more stations.

Source: The OHIO State University

A metal forming process in which a billet (with carefully controlled volume) is deformed (hot or cold) by a punch, in order to fill a die cavity.

Source: The OHIO State University

A die used to change the shape of a sheet metal blank with minimal plastic flow.

Source: The OHIO State University

The ease with which a metal can be shaped through plastic deformation. Evaluation of the formability of a metal involves measurement of strength, ductility, and the amount of deformation required to cause fracture. The term workability is used interchangeably with formability; however, formability refers to the shaping of sheet metal, while workability refers to shaping materials by bulk forming..

Source: The OHIO State University

The plastic deformation of a billet or a blanked sheet between tools (dies) to obtain the final configuration. Metalforming processes are typically classified as bulk forming and sheet forming. Also referred to as metalworking. Making any change in the shape of a metal piece which does not intentionally reduce the metal thickness and which produces a useful shape.

Source: The OHIO State University

Tooling, usually the male part, used for forming sheet metal contours; generally used in rubber-pad forming.

Source: The OHIO State University

A die in which the shape of the punch and die is directly reproduced in the metal with little or no metal flow.

Source: The OHIO State University

A forming limit diagram, which contains a forming limit curve, is used in sheet metal forming for predicting forming behavior of sheet metal. The diagram attempts to provide a graphical description of material failure tests, such as a punched dome test.

Source: Wikipedia

A die constructed so the upper shoe is linked to the lower shoe and not secured in any way to the press ram. Used for blanking or secondary cutting operations. Also called bumper-actuated die.

Source: The OHIO State University