A process involving the heating and cooling of a metal,commonly used to induce softening.The term refers to treatments intended to after mechanical or physical properties or to produce a definite microstructure.
Bead
A narrow ridge in a sheet-metal workpiece or part,commonly formed for reinforcement.
Draw
:(a)A bead used for controlling metal flow
(b)riblike projections on drawing or hold-down surfaces for controlling metal flow.
Bed press:
The stationary and usually horizontal part of a press that serves as a table to which a bolster plate or lower die assembly is mounte.
Bend angle
The angle through which a bending operation is performed.
Bending
The straining of material,usually flat sheet or strip metal,by moving it around a straight axis which lies in the neutral plane.
Bend radius
(a)The inside radius at the bend in the work
(b)The corresponding radius on the punch or on the die.
Blank
A precut metal shape,ready for a subsequent press operation.
Blank development:
(a)The technique of determaining the size and shape of a blank
(b)The resultant flat pattern.
Blankholder
The part of a drawing or forming die which holds the workpiece against the draw ring to control metal flow.
Blanking
The operation of cutting or shearing a piece out of stock to a predetermined contour.
bolster plate
A plate secured to the press bed for locating and supporting the die assembly.
Bulging
The process of expanding the walls of a cup,shell or tube with an internally expanding segmental punch or a punch composed of air,liquids,or semiliquids,such as waxes or tallow, or rubber and other elastomers.
Burnishing
The process of smoothening or plastically smearing a metal surface to improve its finish.
Burr side
The side of a punched blank that presents a rough edge around its periphery or around a hole or opening in it.
Cam action
A motion at an angle to te direction of an applied force,achieved by a wedge or cam.
Carbonitriding
A process in which a ferrous alloy is casehardened by first being heated in a gaseous atmosphere of such composition that the alloy absorbs carbon and nitrogen simultaneously, and then being cooled at a rate that will produce the prroperties desired.
Carburizing:
A process that introduces carbon into a solid ferrous alloy by heating the metal in contact with a carbonaceous material solid,liquid, or gas to a temperature above the transformation range and holding it at that temperature.
Case
The surface layer, or case, of a ferrous aloy that has been made substantially harder than the interior or core.
Casehardening
Any process of hardening a ferrous alloy so that the case or surface is substantially harder than the core or interior.
Clearnce,die
The space per side,between the punch and die.
Clutch
A device which connects and disconects a driven machine member and a driving machine member.
Coining
A closed-die squeezing operation in which all surfaces of the work are confined or restrained.
Crimping
A forming operation used to set down,or close in a seam.
Critical temperatures
Established temperatures to which metals must be heated to produce metallurgical changes such as hardening and normalizing,also known as transformation temperatures.
Cup
Any shallow cylindrical part or shel closed at on end.
Cupping
An operation that produces a cup-shaped part.
Curling
Forming an edge of circular cross section along a sheet or at the end of a shell or tube.
Cushion,hydraulic
A die cushion actuated by hydraulic pressure.
Die height(shut height)
The distance from the finished top face of the upper shoe to the finished bottom face of the lower shoe,immediately after the die operation and with the work in the die.
Die holder
A plate or block upon which the die block is mounted.
Die radius
The radius at the edge of a female die over which metal is formed or drawn into the die.
Die set
A standardized unit consisting of a lower shoe,an upper shoe,and guide pins or posts.
Dimpling
Localized indent forming of sheet metal,so as to permit the head of a rivet or a bolt to fasten down flush with the surface of the sheet.
Distortion
Any deviation from a desired contour or shape.
Draft
The taper given to a die so as to allow the part to fall through the die or be removed.
Drawability
(a)A measure of the feasible deformation of a blank during a drawing process.
(b)Percentage of reduction in diameter of a blank when it is drawn to a shell of maximum practical depth.
Drawing
A process in which a punch causes flat metal to flow into a die cavity to assume the shape of a seamless hollow vessel.
Draw marks
Impressions,such as scratches,burnished areas,and similar marks left on workpieces by draw dies.
Drawpiece
Any drawn part.
Draw radius
The radius at the edge of a die or punch over which the work is drawn.
Drawing
A ring shaped die part(either the die ring itself or a separate ring).over the inner edge of which the metal is drawn by the punch.
Ductility
The property of a material that permits it to sustain permanent deformation in tension without rupture.
Dwell
The time interval in a press cycle during which there is no movement of a press member.
Earing
The formation of ears or scalloped edges around the top edge of a drawn shell due to directional differences in the plasticworking properties of rolled sheet metal.
Ejecting
The removal of a part from a die by an air blast or mechanical means.
Elasticity
The property of a material which renders it capable of some return to its former size and shape after any deformation.
Elastic limit
The maximum stress to which a material can be subjected, and yet return to its original shape and dimensions on removal of the stress.
Embossing
A process that produces relatively shallow indentations or raised designs with theoretically no change in metal thickness.
Extrusion
The plastic flow of a metal through a die orifice.
Eyelet machine
a multiple-side press,usually employing a cut-and-carry or a transfer feed for sequential operations in successive stations.
Feed
A device that moves or delivers stock or workpieces to a die.
Flaring
(a)The process of forming an outward flange on a tubular part;(b)forming a flange on a head.
Flash
The excess metal attached to a part after a forming operation.
Forming
Making any change in the shape of a metal piece which does not intentionally reduce the metal thickness.
Gauge
A device used to position of two metal surfaces in direct sliding contact.
Galling
The friction-induced roughness of two metal surfaces in direct sliding contact.
Gibs,adjustable
Guides or shoes designed to ensure the proper sliding fit between two machine parts.
Ironing
An operaton in which the thickness of the shell wall is reduced and its surface smoothened.
Knockout
A mechanism for ejecting blanks or other work from a die.Commonly located on the side,but may be located under the bolster.
Lancing
Cutting along a line in the orkpiece without producing a detached slug from the workpiece.
lubricant
Any substance which has the specific property of reducing friction between two surfaces in contact.
Necking
Reducing the diameter of a portion of the length of a cylindrical shell.
Nest
(a)To stack like parts within one another to occupy a minimum space;(b)a plate having an opening to conform to the contour of a part,used to locate the part in a die.
Normalizing
A process in which a ferrous alloy is heated to a suitable temperature above the critical range and then cooled in air at room temperature.
Notching
The cutting out of various shapes from the edge of a strip,blank,or part.
Parting
An operation usually performed to produce two or more parts from one common stamping.
Perforating
The piercing or punching of many holes,usually identical and arranged in a regular pattern.
Piercing
The process of die cutting holes in sheet or plate material.
Pilot
A pin or rojection provided for locating work in subsequent operations from a previously punched or drilled hole.
planishing
a hammering operation in which parts are given a dense smooth surface finish by a rapid succession of blows delivered by highly polished dies or by a planishing hammer.
plastic flow
The phenomenon hich takes place when a substance is deformed permanently without rupture.
plasticity
The property of a substance that permits it to undergo a permanent change in shape without rupture.
plastic working
The processing of a substance by causing a permanent change in its shape without rupture.
press
A machine having a stationary bed or anvil,and a slide(ram or hammer)which has a controlled reciprocating motion toward and away from the bed surface and at right angles to it,the slide being guided in the frame of the machine to give a definite path of motion.
Press-brake(bending brake)
An open-frame press for bendingcutting,and forming;usually handling reatively long work in strips.
Puckering
A wavy condition in the walls of a deep drawn part.
Punch
(a)The male tool part,usually the upper member and mounted on the slide;(b)to die-cut a hole in sheet or plate material;(c)a general term for the press operation of producing holes of various sizes in sheets,plates,or rolled shapes.
punch holder
The plate or part of the die which holds the punch.
Quill type punch
A frail or small sized punch mounted in a shouldered sleeve or quill.
Redrawing
Second and following drawing operations in which cuplike shells are deepened and reduced in cross-sectional dimensions.
Relief(undercut or back-off)
Clearance obtained by removing metal,either behind or beyond the cutting edge of a punch or die.
Residual stress
Stresses left within a metal as the result of non-uniform plastic deformation or by drastic gradients of temperature from quenching or welding.
Reverse redrawing(inside-out redrawing)
A second or subsequent redrawing operation,performed in the opposite direction to the original drawing.
roll straightener
A mechanism equipped with rolls to straighten sheet or strip stock,usually used with a feed mechanism for pressworking.
Scrap
pieces or parts not normally usable.
Scrap cutter
A shear or cutter operated by the press or built into a die for cutting scrap into sizes for convenient removal from the die or disposal.
Shaving
A secondary shearing or cutting operation in which the surface of a previously cut edge is finished or smoothened.
Shear
(a)A tool for cutting metal and other material by the closing motion of two sharp,closely adjoining edges;(b)to cut by shearing dies or blades;(c)an inclination between two cutting
shedder
A pin, rod, ring, or plate,operated by mechanical means,air,or a rubber cushion,that either ejects blanks,parts,or adhering scrap from a die, or releases them from punch,die,or pad surfaces.
Shut height of a press
The distance from the top of the bed to the bottom of the side with the stroke down and adjustment up.In general,the shut height of a press is the maximum die height of a press that can be accommodated for normal operation,taking the bolster into consideration.
Sizing
A secondary pressworking operation to obtain dimensional accuracy by metal flow.
Slitting
Cutting or shearing along single lines; used either to cut strips from a sheet or to cut along lines of a given length or contour in a sheet or part.
Slug
A small piece of material,usually scrap,produced in piercing or punching holes in sheet material.
Spalling
the breaking off of flakelike metal particles from a metal surface.
Spotting
The fitting of one part of a die to another,by applying an oil color to the surface of the finished part and bringing it against the surface of the intended mating part,the high spots being marked by the transferred color.
spring-back
The extent to which metal tends to return to its original shape or position after undergoing a forming operation.
Stamp
(a)The general term to denote all pressworking;(b)to impress lettering or designs by pressure into the surface of a material.
Steel rule die
A metal-cutting die employing a thin strip of steel (printer's ruler)formed to the outline of a part and a thin steel punch mounted to a suitable die set.a flat metal plate or block of wood is substituted for the punch when cutting non-metalic materials and soft metals.
Strain
The deformation; or change in size or shape of a body,produced by stress in that body.Unit strain is the amount of deformation (usually in inches)per unit length(usually in inches).
Strain hardening
The increase in hardness and strength in a metal caused by plastic deformation at temperatures lower than the recrystallization range.
Stress
The internal force or forces set up with in a body by outside applied forces or loads.Unit stress is the amount of load per unit area.
Stress cracking
The cracking of parts which have retained residual stresses from cold forming,heat treating,or rapid cooling.
Stress relief
A heat treatment which is done primarily for reducing residual stresses.
Stripper
A device for removing the workpiece or part from the punch.
Stripper plate
A plate (solid or removable)used to strip the workpiece or part from the punch;it may also guide the stock.
Stripping
a device for removing the workpiece or part from the punch.
Stripper plate
A plate (solid or movable)used to strip the workpiece or part from the punch;it may also guide the stock.
Stripping
The operation of removing the workpiece or part from the punch.
Stroke of a press
The reciprocating motion of a press slide,specified as the number of inches between the terminal points of the motion.
Tempering(drawing)
A heat-treating process for removing internal stresses in metal at temperatures above those for stress relieving,but in no case above the lower critical temperature.
Tensile strength
The ultimate strength of a materialmeasured in pounds per square inch in tension on the original cross section tested,which ,if exceeded,causes sectional deformation leading to ultimate rupture.
Trimming
Trimming is the term applied to the operation of cutting scrap off a partially or fully shaped part to an established trim line.
Ultimate strength
The maximum stress which a material can withstand before or at rupture.
Vent
A small hole in a punch or die for admitting air to avoid suction holding,or to relieve pockets of trapped air which would prevent proper die closure or action.
Wrinkling
A wavy condition on metal parts,due to buckling under compressive stresses.
Yield point
The stress at which a pronounced increase in strain is shown without an increase in stress.
