Stamping Operations 125

axis

An imaginary line around which a press makes a bend. The axis in most bending operations is a straight line, but flanging operations can bend metal around a curved axis.

bending

A forming operation that shapes a workpiece by straining it into a desired angle. Bending typically shapes flat workpieces into L-, U-, or V-shaped parts.

binder

A tooling component that holds the workpiece against the die. The binder, also called the draw pad or blank holder, provides pressure that controls the flow of metal into the die cavity during drawing operations.

blade clearance

Space that is intentionally maintained between the upper die tooling and lower die tooling. Blade clearance allows presses to cut metal with shear forces.

blank

A desired piece of sheet metal removed from a larger workpiece. A blank typically undergoes additional operations to form a desired part.

blank holder

A tooling component that holds the workpiece against the die. The blank holder, also called the draw pad or binder, provides pressure that controls the flow of metal into the die cavity during drawing operations.

blank loader

A press component that loads blanks into an automated press. Blank loaders are often used to speed up production or lift blanks that would be too heavy for employees.

blanking

A cutting operation that cuts a desired shape from a workpiece. Blanking removes a section of material from the workpiece to form the desired part.

bolster plate

A flat metal surface attached to the top of the press bed. The bolster plate supports the lower half of the die during stamping operations.

bottoming

The practice of applying additional force to a workpiece after a V-bending operation has formed the desired bend. Bottoming is a strategy manufacturers use to counteract springback.

breakout

The portion of the workpiece's cut edge created by the workpiece fracturing. The breakout, also known as the fracture zone, is typically rough and may contain burrs that require additional processing.

burr

A rough, sharp edge remaining on a part after a cutting process. Burrs must be removed during finishing processes to improve the functionality and appearance of a part.

coining

A forming operation used to create raised surfaces and imprints in metal. Coining requires large amounts of force and creates significant variations in workpiece thickness.

compression

A pushing or pressing force. Compression occurs on the inside of a workpiece that is undergoing bending.

compression flanging

A flanging operation that bends metal along an axis that curves outwards away from the center of the workpiece. Compression flanging, also known as shrink flanging, adds stiffness to the edge of a part.

cut band

The portion of the workpiece's cut edge created by the workpiece experiencing plastic deformation. The cut band, also known as the slip plane or shear zone, is typically smooth.

cutoff

A cutting operation that performs a single cut in order to separate a piece of metal from the original stock. Cutoff creates no scrap.

cutting operations

A stamping operation that penetrates the workpiece to remove or separate sections. Common cutting operations include blanking and punching.

deburring

A finishing process that removes sharp projections left by a tool on a workpiece surface. Deburring can be done by hand or in mass finishing processes.

deep drawing

A drawing operation in which the depth of the completed part is greater than the original workpiece's width. Deep drawing often requires a workpiece to undergo multiple drawing operations to achieve the desired shape.

die set

A series of dies used to create a particular part. A die set consists of multiple dies, each of which performs at least one operation to complete the final part.

dies

A set of tooling components for stamping presses that attach to the slide and bolster plate. Dies perform various stamping operations including cutting and forming metal parts.

draw pad

A tooling component that holds the workpiece against the die. The draw pad, also called the blank holder or binder, provides pressure that controls the flow of metal into the die cavity during drawing operations.

drawing

A forming operation that shapes parts by stretching metal around a punch and forcing it into the die cavity. Drawing operations are often used to create parts with complex contours, such as automotive body panels.

drop

The portion of the workpiece that is cut away. The drop breaks away when the shear force of the press overcomes the shear strength of the workpiece.

edge bending

A bending operation that shapes metal by bending the workpiece along the edge of a die. Edge bending, also known as wipe bending, is efficient for creating a right angle in workpieces.

embossing

A forming operation used to create raised surfaces or lettering in sheet metal. Embossing does not significantly change the workpiece thickness.

fasteners

A device that holds objects together or locates them in relation to one another. Common fasteners include bolts, screws, and rivets.

fine blanking

A type of blanking operation that simultaneously compresses and shears sheet metal to eliminate the roughness of the finished edge. Fine blanking lessens the need for additional operations by producing blanks with edges that are entirely smooth.

finishing

A process that emphasizes tight tolerances and fine details. Finishing operations are usually the final steps in the stamping process.

flanging

A bending operation that bends the edge of a metal part to add stiffness. Flanging creates a 90 degree bend in the metal.

flattening

A bending operation that folds an edge of a sheet metal workpiece back upon itself. Flattening, also called hemming, increases stiffness and can be used to join two pieces of metal.

force

An influence that produces a change in an object's motion or state of rest. Force shapes metal workpieces by pressing them between die components.

forming operations

A stamping operation that shapes sheet metal by exposing it to tension, compression, or both. Forming operations are used to create parts like brackets and automotive frame components.

fracture zone

The portion of the workpiece's cut edge created by the workpiece fracturing. The fracture zone, also known as the breakout, is typically rough and may contain burrs that require additional processing.

hemming

A bending operation that folds an edge of a sheet metal workpiece back upon itself. Hemming, also called flattening, increases stiffness and can be used to join two pieces of metal.

lancing

A cutting operation that shears an interior section of a workpiece without removing it. A lancing operation leaves an open tab that is attached on one side.

lower die tooling

A tooling component that allows space for the metal to be shaped or cut. The lower die tooling typically contains a recess or cavity that matches the upper die tooling.

nesting

The intentional arrangement of a series of parts on sheet metal. Nesting reduces the amount of metal scrap produced during stamping.

notching

A cutting operation that removes a section from the outer edge of a metal strip or part. Notching allows the edges of two parts to fit together more effectively.

overbending

The practice of bending a workpiece just past the desired angle. Overbending is a strategy manufacturers use to compensate for springback.

parting

A cutting operation that performs two cuts simultaneously in order to separate a piece of metal from the original stock. A parting operation produces metal scrap along with the part.

piercing

A cutting operation that creates an open hole in a workpiece by removing an interior section. Piercing, also known as punching, removes an unwanted section of material that becomes discarded scrap.

plastic deformation

The permanent alteration of a material's shape due to stress. A workpiece undergoes plastic deformation before the cut portion of the workpiece fractures.

press

A machine with a stationary base and an upper slide that repeatedly moves up and down. A press shapes or cuts metal to create useful parts for a range of industries.

punch

A tooling component that pushes into or penetrates the workpiece. The punch is a component of the upper half of the die that is used in many stamping operations, including drawing and punching.

punching

A cutting operation that creates an open hole in a workpiece by removing an interior section. Punching, also known as piercing, removes an unwanted section of material that becomes discarded scrap.

restriking

A stamping operation that repeats a previous drawing operation. Restriking operations add details to the workpiece and counteract springback.

ribs

A relatively narrow and shallow protruding linear feature on a sheet metal part. Ribs add stiffness and help parts resist deformation and warping.

right angle

An angle that measures 90 degrees. A right angle is formed by two perpendicular lines or objects.

rotary bending

A bending operation in which specialized die components convert the vertical motion of the press into circular motion that bends the workpiece. Rotary bending requires less force than other bending methods.

scrap

A piece of unusable material produced during a manufacturing process. Scrap from stamping operations can often be minimized by using techniques like nesting to reduce the space between parts on a workpiece.

seaming

A bending operation that joins the edges of a workpiece by interlocking them. Seaming folds two hems around one another.

secondary operations

An additional manufacturing process required to bring a workpiece into tolerance and create a final part. Secondary operations for stamped parts include removing rough edges, cleaning, and assembly.

shaving

A cutting operation that removes rough edges from a previously cut edge. Shaving operations produce a minimal amount of scrap.

shear force

A force that attempts to cause the internal structure of a material to slide against itself. Enough shear force will cause the material to separate.

shear strength

The ability of a material to resist forces that attempt to cause the internal structure to slide against itself and separate. Shear strength is the amount of shear force a material can withstand before fracturing.

shear zone

The portion of the workpiece's created by the workpiece experiencing plastic deformation. The shear zone, also known as the slip plane or cut band, is typically smooth.

sheet metal

A flat metal stock. Sheet metal used in stamping operations is commonly steel with thicknesses ranging from 0.001-0.625 inches (0.0254-15.875 mm).

shrink flanging

A flanging operation that bends metal along an axis that curves outwards away from the center of the workpiece. Shrink flanging, also known as compression flanging, adds stiffness to the edge of a part.

slide

The upper portion of a stamping press that moves up and down within the press frame during operation. The slide, sometimes called a ram, provides the required force to complete stamping operations.

slip plane

The portion of the workpiece's cut edge created by the workpiece experiencing plastic deformation. The slip plane, also known as the shear zone or cut band, is typically smooth.

slug

The unwanted portion of a workpiece removed by a punching operation. A slug is unusable scrap that is collected or removed by components in the press bed.

specifications

A description of the essential physical and technical properties of a finished part. Specifications outline important information including finished part dimensions and acceptable tolerance ranges.

springback

The tendency of a material that has been shaped to revert to its original form. Springback can make parts fall outside design tolerances if not accounted for.

straight flanging

A flanging operation that bends metal along a straight axis. Straight flanging is adds stiffness to the edge of a part.

stresses

A force that attempts to deform an object. Common stresses include compression force, shear force, and tensile force.

stretch flanging

A flanging operation that bends metal along an axis that curves inward toward the center of the workpiece. Stretch flanging, also known as tension flanging, adds stiffness to the edge of a part.

stroke

The reciprocating motion of the slide. One stroke is one complete cycle of the slide's up-and-down motion.

tension

A pulling force that attempts to stretch or elongate an object. Tension occurs on the outside of a workpiece that is undergoing bending.

tension flanging

A flanging operation that bends metal along an axis that curves inward toward the center of the workpiece. Tension flanging, also known as stretch flanging, adds stiffness to the edge of a part.

tolerances

The unwanted but acceptable deviation from a specified dimension. Tolerances indicate the allowable difference between a physical feature and its intended design.

tooling

Assorted tools used in manufacturing processes. Tooling used in stamping includes dies.

trimming

A cutting operation that removes an uneven section from the top rim of a previously worked part. Trimming operations typically follow forming operations on sheet metal.

upper die tooling

A tooling component that pushes into or penetrates the workpiece. The upper die tooling is a component of the upper half of the die that typically matches the recess in the lower half of the die.

V-bending

A bending operation that shapes the workpiece by forcing it into a V-shaped die. V-bending can produce bends at a variety of precise angles.

wipe bending

A bending operation that shapes metal by bending the workpiece along the edge of a die. Wipe bending, also known as edge bending, is efficient for creating a right angle in workpieces.

wiping die

Tooling used in wipe bending operations. A wiping die uses a punch to bend the extended edge of the workpiece down along the side of the die.

workpiece

A part that is being worked on during manufacturing. The workpiece in stamping is often a sheet or coil of thin metal.