Source: Tooling University

 

Sections:

Press Basics
This class introduces common presses, their main components and functions.

Stamping Safety
This class describes general safety practices that all people in the shop must observe during a press operation.

Punch and Die Operations
This class introduces the common sheet metal operations performed with the help of dies and presses.

Die Components
This class introduces dies, their main components and function within a press.

Coil Handling Equipment
This class describes the equipment used in a coil-fed press line and explains general coil line arrangements.

Die Cutting Variables
This class describes the steps that take place during a cutting operation and shows how clearance impacts the cutting process.

Monitoring Press Operations
This class describes how to use the basic controls on a typical press and explains how a press operator monitors the press operation.

Guiding System Components
This class describes common guiding system components used in die sets, as well as their advantages and disadvantages.

Stripper System Components
The class describes the major types of strippers and springs used in die sets, as well as their advantages and disadvantages.

Coil Loading Procedures
This class explains how to properly handle and load coil onto the uncoiler, as well as describes how to thread the straightener and feed coil stock into the die area.

Die Setting Procedures
This class describes how to change a die and explains proper setup procedures for die setting.

 

 


 

Press Basics:

 

 

Term

Definition

arch press

A type of press similar to a straight-side press with an enlarged bed and bell-shaped frame. The arch press can accommodate larger sheets of metal.

bed

The main foundation and supporting structure upon which the operating parts of the machine are mounted and guided.

bending

The shaping of sheet metal by straining the metal around a straight axis. A bending operation compresses the interior side of the bend and stretches the exterior side. Flanging, hemming, and seaming are all bending operations.

blanking

A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired section.

bolster plate

A plate that is designed to hold in place the lower die shoe. The bolster plate is attached to the top surface of the press bed.

capacity

The specified amount of force that a press is capable of exerting near the bottom of its stroke in order to carry out a stamping operation.

C-frame press

Another term for the gap-frame press.

cold working

The shaping of metal at temperatures much lower than the metal's molten state, often at room temperature. Cold working adds certain properties to the metal, such as increased strength and improved surface finish.

crankshaft

The device in some mechanical presses that connects the ram to the flywheel.

crown

The upper portion of a press containing the drive mechanisms or cylinders that guide the reciprocating motion of the ram.

cylinder

The main drive of a hydraulic press that uses fluid to force the motion of a piston encased within the device.

deep drawing

A drawing operation performed on sheet metal that creates a hollow shape with a depth greater than its width.

deflection

The amount of deviation from a straight line or plane when a force is applied. Effective presses reduce the amount of deflection during operation.

die

The tool typically attached to the lower portion of the die set containing a recess that provides space for the shaping or shearing of sheet metal.

die set

The collective assembly of upper and lower die shoes, guide pins and bushings, and punch and die holders.

drawing

For sheet metal, a forming operation that transforms a flat disc of stock into a hollow cup with an enclosed bottom. Drawing operations can also create boxes and more intricate shapes as well.

eccentric drive

A drive that uses an offset section to power the reciprocating motion of the ram.

flanging

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

flywheel

The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram.

frame

The structure of a press that supports the ram above the base and guides the reciprocating motion of the ram.

gap-frame press

A type of press with a C-shaped frame suspending the crown over the bed and an open portion in the front. The open front of the gap-frame press offers easy access to the die set.

horn press

A type of press with a cylindrical projection designed to position sheet metal parts for secondary operations.

hot working

The shaping of metal at temperatures close to the metal's molten state. Metal that has been hot worked is often left with a rough, scaly exterior.

hydraulic power

Power derived from the motion and pressure of a fluid, such as water or oil.

hydraulic press

A press that is driven by hydraulic power. Most hydraulic presses are driven by one or more cylinders that use fluid pressure.

lower die shoe

The lower plate of a die set that contains the cavity into which the punch shears the sheet metal.

mechanical power

Power derived from the use of solid tooling and machinery.

mechanical press

A press that is driven by mechanical power. Most mechanical presses are driven by a flywheel, crank, and clutch.

metal forming

The plastic deformation of a metal in order to produce a useful shape. Sheet metal can be formed through operations that shear, stretch, bend, or compress the metal.

open-back inclinable press

A type of gap-frame press with a bed and frame that can be tilted backwards to encourage the removal of parts after they are separated from the strip.

press

A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.

press brake

A type of press with an open frame and wide, narrow bed. Press brakes are often used for bending operations, and they are typically manually operated.

punch

The tool typically attached to the upper portion of the die set that shapes or penetrates the sheet metal.

punching

A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.

ram

The main upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the ram.

seaming

A bending operation that joins the interlocking edges of two separate metal sheets together by folding them over one another.

shear force

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

shear strength

The ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself.

stamping

The process of forming sheet metal at room temperature with the use of dies and punches.

straight-side press

A type of press with supporting columns in each corner of the frame suspending the crown over the bed. The straight-side press offers improved rigidity and reduced deflection.

stroke

The distance marked by the farthest ends of reciprocating vertical movement of the press ram.

turret press

A type of press with an open frame and a turret containing multiple punches. Turret presses are mostly used to perform a variety of shearing operations, and they are typically numerically controlled.

upper die shoe

The upper plate of a die set that secures the punch holder.


 

Stamping Safety:

 

 

Term

Definition

adjustable panel guard

An adjustable barrier guard that prohibits access to the die area during a press operation.

barrier guard

A type of safeguarding device that forbids entry into the point of operation while the press cycles.

coil-fed press operation

A type of press operation in which raw material is fed to the press from a coil. The press operator needs only to press a button to begin stamping, and the press continuously stamps out parts until it recieves a stop signal.

continuous mode

A mode of press operation in which the ram strokes multiple times uninterrupted. Continuous mode is also known as production mode.

crankshaft

The device in some mechanical presses that connects the ram to the flywheel.

die area

The area that contains the die. Press operators should only enter the die area with approved handling tools.

die safety block

A safety device that is placed between the die shoes to ensure that the press cannot accidentally cycle during maintenance work.

dual palm buttons

Two separate buttons that must be pressed simultaneously in order to power the stamping press. Dual palm buttons are considered safeguarding devices.

earmuffs

Ear wear that protects hearing. Earmuffs also prevent flying objects from entering the ear.

earplugs

Ear wear that protects hearing. Earplugs are inserted inside the ear to muffle outside noises.

E-stop

Another name for the red stop button. "E-stop" is short for "emergency stop".

feed chute

A pathway attached to the press that feeds material to the die area.

fixed panel guard

A barrier guard that prohibits access to the die area at all times during a press operation. Fixed panel guards cannot be adjusted.

flywheel

The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram.

foot switch

An operator control that requires press operators to insert their foot into a guard, and press a button in order to operate the press.

forward and reverse key selector

A locked, key-operated control on the press that selects the direction in which the motor turns the crankshaft.

full-revolution clutch press

A type of press in which the clutch, when it is tripped, cannot be disengaged until the crankshaft has completed a full revolution and the ram a full stroke.

hand vacuum tool

A type of handling tool that allows press operators to enter the die area without using their hands.

holdouts

A safeguarding device that requires the press operator to wear wristbands. Holdouts do not allow the press operator to enter the point of operation at any time.

inch mode

A mode of press operation in which the ram moves intermittently at different points in the stroke. Inch mode is most often used during die setup and before loading a new coil.

interlock plug

A device that attaches to the die safety block to prevent the press from cycling when the die safety block is in place.

light curtain

A row of either visible or invisible lights just before the point of operation. If the path of the lights is disturbed, the press stops cycling immediately.

lockout

A safety procedure required by OSHA that takes steps to dissipate all stored energy during maintenance work. Never try to operate a machine that is under lockout.

lower die shoe

The lower plate of a die set that contains the cavity into which the punch shears the sheet metal.

magnetic lifter

A type of handling tool that allows the press operator to enter the die area without using their hands. A magnetic lifter uses magnets to easily pick up scraps and workpieces.

main motor start and stop button

Either one or two buttons on the stamping press that turn the press main motor on and off.

manually fed press operation

A type of press operation in which an operator inserts a part into the die, then presses a button to cycle the press.

mode selector

A locked, key-operated control on the press that selects the proper mode of operation for the stamping press.

Occupational Safety and Health Administration

A government agency that sets the standards for working conditions in the United States. OSHA ensures that employees work in safe and healthy environments.

operator controls

The controls on the press that, when depressed, cause the press to cycle. Operator controls often contain safety devices that prevent the press from cycling accidentally.

OSHA

The abbreviation for the Occupational Safety and Health Administration.

part-revolution clutch press

A type of press in which the clutch, when it is tripped, can be disengaged at any point before the crankshaft has completed a full revolution and the ram a full stroke.

parts conveyor

A long belt that rotates to remove parts or scrap from the die area.

personal protection equipment

Any of various articles of clothing or safeguarding devices that press operators are required to wear. Personal protection equipment (PPE) varies from shop to shop.

point of operation

The area between the lower die shoe and the upper die shoe where metal forming takes place.

press

A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.

press operator

The individual who monitors and operates the stamping press.

pullback cables

A safeguarding device that requires the press operator to wear wristbands. When the press cycles, pullback cables pull back to ensure that the press operator's hands do not go near the point of operation.

ram

The main upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the ram. The ram can also be referred to as the slide.

red stop button

A red button on the stamping press that, when pressed on part-revolution clutch presses, stops the press immediately. The red stop button is often referred to as E-stop.

safeguarding device

A device used to protect the operator from the point of operation. The type of safeguarding devices used depends on the shop and type of stamping press.

safety tongs

A type of handling tool that allows press operators to enter the die area without using their hands. A press operator manipulates the tongs to grab the part from the die area.

single stroke mode

A mode of press operation in which the ram completes one stroke. Single stroke mode is often used in manually fed operations.

slide

The upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the slide. The slide is also referred to as the ram.

sliding gate

A barrier guard that slides down each time the press cycles to prohibit access to the point of operation during a press operation.

straightener

A mechanism designed to repeatedly bend stock back and forth to remove any natural curvature.

stroke-up position

The position of the ram at the top of its cycle.

top dead center

The highest position in the ram's stroke. TDC is also referred to as stroke-up position.

top stop button

Another name for the yellow stop button.

uncoiler

A mechanism designed to hold coil and gradually unwind it during press operations.

upper die shoe

The upper plate of a die set that secures the punch holder.

yellow stop button

A yellow button on the stamping press that stops the press once it reaches the stroke-up position. The yellow stop button is often referred to as the top stop button.

 


 

Punch & Die Operations:

 

 

Term

Definition

axis

An imaginary straight line that is used to measure the dimensions of an object.

bar stock

Raw material purchased from metal manufacturers in the form of long cylindrical bars.

beading

Another term used for a curling operation.

bending

The shaping of sheet metal by straining the metal around a straight axis. A bending operation compresses the interior side of the bend and stretches the exterior side. Flanging, hemming, and seaming are all bending operations.

blank

The section of sheet material resulting from a blanking operation that is usually subjected to further metalworking operations.

blanking

A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired section.

bulging

A forming operation that increases the diameter of a portion of a hollow cylindrical part. Bulging also slightly shortens the part, and it requires the use of a rubber punch or pressurized fluid.

chip

An unwanted piece of metal that is removed from a workpiece. Numerous chips are formed when a tool cuts or grinds metal.

clearance

The amount of space between the outer edge of the punch and the inner edge of the die cavity. A proper amount of clearance is necessary for an effective shearing operation.

coining

A metalworking operation used to create raised surfaces and imprints in metal. Coining is a relatively severe operation that creates variations in metal thickness.

cold working

The shaping of metal at temperatures much lower than the metal's molten state, often at room temperature. Cold working adds certain properties to the metal, such as increased strength and improved surface finish.

curling

A forming operation that creates a curved rim around the top of a hollow part.

cutoff

A shearing operation that performs a single cut in order to separate a piece of metal from the original stock. Each cut separates a new part.

die

The tool typically attached to the lower portion of the die set containing a recess that provides space for the shaping or shearing of sheet metal.

drawing

For sheet metal, a forming operation that transforms a flat disc of stock into a hollow cup with an enclosed bottom. Drawing operations can also create boxes and more intricate shapes as well.

edge bending

A bending operation performed by compressing the sheet metal between two flat dies and using a punch to bend an extended portion of the sheet over the lower corner of the wiping die.

embossing

A metalworking operation used to create raised surfaces or lettering in sheet metal. There is theoretically no change in metal thickness during embossing.

fine blanking

A type of blanking operation that simultaneously compresses and shears sheet metal in order to reduce the amount of tearing along the edge. Fine blanking produces blanks with edges that are entirely smooth.

flanging

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

flattening

Another term used for a hemming operation.

forming

The plastic deformation of a metal in order to produce a useful shape. Sheet metal can be formed through operations that shear, stretch, bend, or compress the metal.

hardness

The ability of a material to resist penetration and scratching. Hardness is one of the mechanical properties of a given material.

hemming

A bending operation that bends and folds an edge of sheet metal back upon itself. Hemming conceals the sharp edge of sheet metal.

hot working

The shaping of metal at temperatures close to the metal's molten state. Metal that has been hot worked is often left with a rough, scaly exterior.

lancing

A shearing operation that cuts an interior section of the metal without removing the section. A lancing operation leaves an opened metal tab.

necking

A forming operation that reduces the diameter of a portion of a hollow cylindrical part. Necking also slightly lengthens the part.

nesting

The arrangement of a series of part dimensions on sheet metal that attempts to reduce the amount of metal scrap produced during the press operation.

notching

A shearing operation that removes a section from the outer edge of the metal strip or part.

parting

A shearing 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

Another term for a punching operation. For various manufacturers, the term "piercing" refers to a punching operation that does not produce a slug, or it is used in a more general sense.

plastic deformation

Deformation that is permanent. Plastic deformation occurs after excessive elastic deformation.

press

A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.

punch

The tool typically attached to the upper portion of the die set that shapes or penetrates the sheet metal.

punching

A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.

seaming

A bending operation that joins the interlocking edges of two separate metal sheets together by folding them over one another.

shaving

A shearing operation that smooths and finishes a previously cut edge. Shaving operations produce a minimal amount of scrap.

shear strength

The ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself.

shearing

The cutting and separating of material without the formation of chips. Punching, piercing, lancing, parting, notching, and shaving are all shearing operations.

sheet metal

Flat metal stock with a thickness greater than 1/64 in. and no larger than 1/4 in.

shrink flange

A flanging operation that creates a bent edge that curves outward in the center.

slug

The discarded section of metal resulting from a punching operation.

springback

The tendency for sheet metal to return to its original shape after a bending or forming operation.

strength

The ability of a metal to resist forces that attempt to break or deform the metal. A material exhibits tensile, compression, or shear strength, depending on the direction of the force.

stretch flange

A flanging operation that creates a bent edge that curves inward in the center.

swaging

Another term used for a necking operation.

tolerance

The unwanted but acceptable deviation from a desired dimension. The tighter the tolerance, the greater the cost to manufacture the part.

trimming

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

V-bending

A bending operation performed by compressing the sheet metal between a matching V-shaped punch and die.

wiping die

The tool used in an edge bending operation that provides the corner over which the extended portion of sheet metal is bent.

 


 

Die Components:

 

 

Term

Definition

air bending

A bending operation performed by using a punch to force the sheet into a die cavity without a bottom.

bed

The main foundation and supporting structure upon which the operating parts of the machine are mounted and guided.

bending

The shaping of sheet metal by straining the metal around a straight axis. A bending operation compresses the interior side of the bend and stretches the exterior side.

blankholder

The tool in a drawing die that holds down the outer rim of the metal sheet as it is drawn into the die cavity.

blanking

A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired section.

bolster plate

A plate that is designed to hold in place the lower die shoe. The bolster plate is attached to the top surface of the press bed.

clearance

The amount of space between the outer edge of the punch and the inner edge of the die cavity. A proper amount of clearance is necessary for an effective shearing operation.

combination die

Another term for a compound die. For some manufacturers, the term "combination die" implies a die that both cuts and forms the metal.

compound die

A die designed to simultaneously perform more than one operation with each stroke of the press. For example, a compound die may blank and pierce in a single stroke.

die

The main tool typically attached to the lower portion of the die set. The die contains a recess that provides space for the shaping or shearing of sheet metal.

die button

A hardened steel tube that provides the opening for the punch during operation. During a shearing operation, the slug or blank passes through this opening.

die holder

Another term used for the lower die shoe.

die retainer

A hardened steel block containing machined impressions or cavities that shape the metal as the punch descends from above. The die retainer also holds the die button.

die set

The collective assembly of upper and lower die shoes, guide pins and bushings, and punch and die retainers.

drawing

For sheet metal, a forming operation that transforms a flat disc of stock into a hollow cup with an enclosed bottom. Drawing operations can also create boxes and more intricate shapes as well.

edge bending

A bending operation performed by compressing the sheet metal between two flat dies and using a punch to bend an extended portion of the sheet over the lower die corner.

ground

Machined with an abrasive to achieve a very precise dimension with excellent finish.

guide post

A hardened rod positioned in the lower die shoe that fits into a bushing in the upper die shoe to guide the punch during operation.

guide post bushing

A hardened steel tube that slides over the guide post and directs the upper die shoe during operation.

hardness

The ability of a material to resist scratching or penetration.

lower die shoe

The lower plate of a die set that supports the die retainer and die button.

matrix

Another term used for the die button.

pilot

A long, slender punch with a rounded tip used to position the metal sheet by entering a previously formed hole. Pilots are longer so that they enter the sheet before other tools form the metal.

plain-carbon steel

A basic grade of steel, which contains less than 3 percent of elements other than iron and carbon.

press brake

A type of press with an open frame and very wide bed. Press brakes are often used for bending operations, and they are typically manually operated.

progressive die

A die containing a series of stations that perform one press operation after another in series. A progressive die gradually forms a part as it moves through the die, and the last operation separates the part.

punch

The tool typically attached to the upper portion of the die set that shapes or penetrates the sheet metal.

punch holder

Another term for the upper die shoe.

punch press

A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.

punch retainer

The device used to mount the punch on the upper die shoe.

punching

A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.

ram

The main upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the ram.

slug

The discarded section of scrap produced by a punching operation.

station

A position within a progressive die where a punch and die perform a single metalworking operation. Progressive dies consist of a series of stations.

stripper

A plate designed to remove sheet metal stock from the punch as it pulls away from the die during the operation.

stroke

The distance marked by the farthest ends of reciprocating vertical movement of the press ram.

tool steel

A type of steel designed for excellent wear resistance, toughness, and strength. Tool steels are typically variations of high-carbon steels.

toughness

The ability of a metal to absorb energy without breaking or fracturing.

upper die shoe

The upper plate of a die set that secures the punch retainer.

V-bending

A bending operation performed by compressing the sheet metal between a V-shaped punch and die.

wiping die

The tool used in an edge bending operation that provides the corner over which the extended portion of sheet metal is bent.

 


 

Coil Handling Equipment:

 

 

Term

Definition

bridge grip feeder

A type of grip feeder that clamps stock in the center or across its entire width.

coil

A long, thin sheet of metal that has been wound tightly. Stock first appears as coil for many press operations.

coil set

The natural curvature remaining in coil after it has been unwound.

conveyor

A long belt that rotates to remove parts or scrap from the die area.

cradle

A type of uncoiler that supports coil from below on its outside diameter.

eccentric drive

A powered drive that uses an offset section to power the reciprocating motion of the ram.

feed gripper

The device on a grip feeder that clamps/unclamps and slides back and forth to advance stock into the die.

feed mechanism

A mechanism designed to intermittently advance stock into the press between strokes.

feed roll

A cylindrical component on a roll feeder that rotates to advance stock into the die.

grip feeder

A type of feed mechanism that uses one stationary and one sliding clamping mechanism to intermittently feed stock into the press.

idler roll

An unpowered component on a straightener that bends stock as it passes through the equipment. Idler rolls are positioned above the stock.

inside diameter

An interior cylindrical surface of a hole.

intermittent

Moving in a repetitive, constant start-and-stop cycle.

keeper

A component on a reel uncoiler that prevents the coil from sliding off the mandrels.

loop control device

A device that detects when stock must be advanced to maintain the slack loop. Either a powered uncoiler or straightener will typically have a loop control device.

mandrel

A component on a reel uncoiler that holds coil through its inside diameter. Mandrels expand to hold the coil in place.

mechanical roll feeder

A roll feeder that is powered with energy supplied by the press itself. Mechanical roll feeders require rods connected to the press eccentric drive.

open-throat grip feeder

A type of grip feeder that clamps stock on one edge. Open-throat grip feeders can accommodate wider stock.

outside diameter

An exterior cylindrical surface of a part or stock.

pilot

A long, slender punch with a rounded tip used to position the metal sheet by entering a previously formed hole.

pinch roll

A component on a cradle uncoiler that assists uncoiling by pulling on the stock.

ram

The main upper portion of the press that slides up and down within the press frame during operation.

reel

A type of uncoiler that holds coil by its inside diameter and suspends it above the ground.

rest roll

A component on a cradle uncoiler that supports the coil and rotates to unwind the coil.

retainer gripper

The stationary device on a grip feeder that clamps and unclamps to assist in advancing stock.

roll feeder

A type of feed mechanism that uses rotating rolls to intermittently feed stock into the press.

scrap chopper

A mechanism designed to cut scrap into smaller sections to facilitate handling.

servo-driven roll feeder

An independent roll feeder that has powered, computer-controlled rolls.

shaker

A special chute that reciprocates back and forth to remove parts or scrap from the die area.

side plate

A component on a cradle uncoiler that prevents the coil from tipping on its side.

slack loop

Excess stock that hangs between coil-line equipment. The slack loop allows continuous and intermittent equipment to work together.

straightener

A mechanism designed to repeatedly bend stock back and forth to remove any natural curvature.

straightening roll

A powered component on a straightener that bends and passes stock through the equipment. Straightening rolls are positioned below the stock.

uncoiler

A mechanism designed to hold coil and gradually unwind it during press operations.

 


 

Die Cutting variables:

 

 

Term

Definition

angular clearance

The enlarged section below the die opening that allows the blank to fall from the die.

blanking

A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired part.

break off

A practical term for the rough, fractured ring surrounding the edge of a blank.

burnishing

The creation of a shiny, polished surface on metal due to a shearing action.

clearance

The space between the punch and the die that allows metal to be cut.

compressive force

A force or pressure that attempts to flatten or squeeze a material.

cut band

A practical term for the burnished ring surrounding the edge of a blank.

deflection

The misalignment of components due to various stresses.

deformation

The moment during which the punch penetrates the sheet and metal flows into the die opening. Deformation and penetration cause the edge radius and burnished ring.

double breakage

The condition of two separate deformation stages caused by insufficient clearance. Double breakage causes two burnished rings on the blank edge.

edge radius

A rounded edge on a blank caused by the initial deformation as the punch begins to enter the die.

fracture

The moment during which cracks form and the blank separates with a tearing action. Fracture causes the roughened break off section on the edge.

lubricant

A fluid designed to reduce friction and cutting forces during a stamping operation.

punching

A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.

shear strength

The ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself.

shearing

The cutting and separating of material without the formation of chips.

snap-through

The moment during which the blank separates from the sheet and compressive forces are released from the die components.

stripper

A plate designed to remove sheet metal stock from the punch as it pulls away from the die during the operation.

stripping

The moment during which the punch retracts from the die and is removed from the sheet.

taper

An angled surface that appears on the edge of a blank. Taper is the result of clearance between the punch and die.

tensile strength

The ability of a material to resist forces that attempt to pull it apart or stretch it.

 


 

Monitoring Press Operations:

 

 

Term

Definition

arm control

A control on the press that prepares for the press to begin in continuous mode. The arm control prevents inadvertent startup of the press when it is in continuous mode.

automatic single stroke mode

A mode of press operation in which the ram completes a single press stroke at a time automatically until it is overridden by another sensor.

auxiliary sensor

A secondary sensor, which helps signal the press to stop.

bed

The main foundation and supporting structure upon which the operating parts of the press are mounted and guided.

bottom dead center

The lowest position in the ram's stroke. BDC is also referred to as stroke-down position.

clutch

The coupling mechanism used on a press to couple the flywheel to the crankshaft, either directly or through a gear train.

coil

A long, thin sheet of metal that has been wound tightly. Stock first appears as coil for many press operations.

continuous mode

A mode of press operation in which the ram strokes multiple times uninterrupted. Continuous mode is also known as production mode.

crankshaft brake

The mechanism used on the press to stop or hold the crankshaft when the clutch is disengaged.

die assembly

The collective assembly of upper and lower die shoes, guide pins and bushings, and punch and die retainers.

die shoes

A metal plate onto which the various die set components are mounted. Die sets typically contain an upper and lower die shoe.

drive mechanism

A mechanism that forces the top section of the press, or ram, down toward the base of the machine.

dual inch buttons

Another name for the dual palm buttons when operating in the inch mode.

dual palm buttons

Two separate buttons that must be pressed simultaneously in order to power the stamping press. The dual palm buttons initiate motion of the ram.

ejection chute

A pathway attached to the press that removes parts or scrap from the die area.

E-stop

Another name for the red stop button.

feed chute

A pathway attached to the press that feeds material to the die area.

feed mechanism

A mechanism designed to intermittently advance stock into the press between strokes.

fiber optic sensor

A type of sensor that uses a bundle of transparent fibers of plastic or glass to transmit light and send a signal to the press if it detects a problem.

flywheel

The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram.

full-revolution clutch presses

A type of press in which the clutch, when it is tripped, cannot be disengaged until the crankshaft has completed a full revolution and the ram a full stroke.

inch mode

A mode of press operation in which the ram moves intermittently at different points in the stroke. Inch mode is most often used during die setup and before loading a new coil.

interlocked barrier guard

A type of safeguarding device that forbids entry into the point of operation while the press cycles.

jogging

Moving the press intermittently up and down to different points in the stroke.

light curtain

A row of either visible or invisible lights just before the point of operation. If the path of the lights is disturbed, the press stops cycling immediately.

lockout

A safety procedure required by OSHA that takes steps to dissipate all stored power during maintenance work. Never try to operate a machine that is under lockout.

main motor start/stop button

Either one or two buttons on the stamping press that both allow the press to begin cycling and subsequently stop the press from cycling.

malfunction sensor

A sensor on the press that detects a problem and signals the press to stop.

micrometer

A hand-held measuring device used to inspect the dimensions of parts. The typical micrometer is accurate within 0.001 in. or 0.02 mm.

mode selector

A locked, key-operated control on the press that selects the proper mode of operation for the stamping press.

operator controls

The controls on the press that, when depressed, cause the press to cycle. Operator controls often contain safety devices that prevent the press from cycling accidentally.

part-revolution clutch presses

A type of press in which the clutch, when it is tripped, can be disengaged at any point before the crankshaft has completed a full revolution and the ram a full stroke.

photoelectric sensor

A type of sensor on the press that emits an electric beam, and when the beam is interrupted, sends a signal to the press to stop the operation.

press

A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.

press operator

The person who operates and monitors the stamping press.

proximity sensor

A type of sensor on the press that detects the closeness of an object or material and sends a signal to the press if a problem is detected.

ram

The main upper portion of the press that slides up and down within the press frame during operation.

red stop button

A red button on the stamping press that when pressed on part-revolution clutch presses, stops the press immediately. The red stop button is often referred to as E-stop.

scrap conveyor

A long belt that rotates to remove parts or scrap from the die area.

sensing devices

A device that is designed, constructed, and arranged to create a sensing field or area and to deactivate the clutch control of the press when the body part of an operator is within this field or area.

single stroke mode

A mode of press operation in which the ram completes one stroke. Single stroke mode is often used in manually fed operations.

straightener

A mechanism designed to repeatedly bend stock back and forth to remove any natural curvature.

stroke-up position

The position of the ram at the top of its cycle.

tonnage monitor

A device that checks and records the amount of pressure being exerted on the die. If there is too much pressure on the die, the tonnage monitor will signal the press to stop.

top dead center

The highest position in the ram's stroke. TDC is also referred to as stroke-up position.

top stop button

Another name for the yellow stop button.

uncoiler

A mechanism designed to hold coil and gradually unwind it during press operations.

yellow stop button

A yellow button on the stamping press that stops the press once it reaches the stroke-up position. The yellow stop button is often referred to as the top stop button.

 


 

Guiding System Components:

 

 

Term

Definition

aluminum alloy

A silvery white metal that is soft, light, and has a high strength-to-weight ratio.

ball bearing system

A guiding system consisting of ball cages that position ball bearings between the guide post and bushing surfaces. Ball bearing systems require less lubrication and offer improved alignment.

ball cage

A component attached to a guide post that houses multiple ball bearings. Ball cages travel along the guide post during operation.

bearing

A hardened, spherical ball that spins between two surfaces and reduces friction.

boss

A general term for any protrusion or component that "sticks out."

bronze

An alloy of copper and tin. Bronze offers a balance of strength, wear resistance, and corrosion resistance.

bushing

A hardened metal tube assembled in a die shoe that fits over a matching guide post.

clearance

A type of fit designed with a small amount of space for easy removal.

die shoe

A metal plate onto which the various die set components are mounted. Die sets typically contain an upper and lower die shoe.

graphite

A soft, black carbon-based material that can be used as a lubricant.

grinding

The use of an abrasive tool to wear away at a surface. Grinding is often used to tighten tolerances and improve surface finish.

guide post

A hardened cylindrical rod used to guide and align the die shoes. Guide posts are fitted into a matching bushing.

guiding system

The assembled components within a die set responsible for the proper alignment and guidance of the die shoes.

heel block guiding system

A guiding system that incorporates bosses and wear plates to increase rigidity.

honing

A precision abrasion process in which a relatively small amount of material is removed from a surface by means of abrasive stones.

interference

A type of fit designed with a small degree of overlap to prevent removal.

lubricant

A fluid used to reduce the friction between components.

oil groove

A patterned, internal channel or slot within a bushing that encourages the flow of a lubricant.

plain bearing system

A guiding system consisting of plain guide posts and bushings with finished surfaces that directly contact one another. Plain bearing systems require lubrication.

porosity

The amount of small spaces or voids within a solid material. Porous materials can absorb fluids.

preloading

An intentional interference fit between a guide post and bushing. Ball bearing systems are often preloaded.

press fit bushing

A type of bushing designed for an interference fit within the die shoe.

press fit guide post

A type of guide post designed for an interference fit within the die shoe.

self-lubricating bushing

A bushing containing numerous graphite plugs that store and slowly release a lubricating oil.

shoulder

A ring or collar around a component that provides a clamping surface.

slip fit bushing

A type of bushing designed for a clearance fit within the die shoe. Slip fit bushings are held in place with clamps.

slip fit guide post

A type of guide post designed for a clearance fit within the die shoe. Slip fit guide posts are held in place with clamps.

steel

A metal consisting of iron and carbon, usually with small amounts of other elements. Steel is the most common manufacturing metal.

stroke length

The distance marked by the farthest ends of reciprocating vertical movement of the press ram.

toe clamp

A type of clamp with a serrated surface that reaches forward and down to grip the workpiece.

wear plate

A component used to reduce wear and add support. Wear plates used within die sets often contain self-lubricating graphite plugs.

 


 

Stripper System Components:

 

 

Term

Definition

chrome silicon spring

A mechanical spring made from steel containing the alloys chromium and silicon.

chrome vanadium spring

A mechanical spring made from steel containing the alloys chromium and vanadium.

deep drawing

A press operation that creates a hollow recess or cavity within sheet metal. The depth of the recess is greater than the width of the part.

deflection

The distance that a spring travels under a compressive force.

fixed stripper

A stripper that does not move within the die set. Fixed strippers strip the stock from the punch, but they do not hold down the stock during operation.

floating stripper

A stripper that is designed to move as press ram reaches the bottom of its stroke. Floating strippers hold down the stock during the stamping operation and strip the stock.

ISO

The International Organization for Standardization. ISO establishes standards and guidelines for various products and processes. ISO standards often contain metric units.

mechanical spring

A spring consisting of a coil of metal with a hollow center. Each mechanical spring is categorized according to the compressive force it can withstand.

mechanical spring stripper

A stripper consisting of a stripper plate and mechanical springs.

nitrogen spring

A spring consisting of a cylinder containing compressed nitrogen gas that applies pressure to a moveable piston.

nitrogen spring stripper

A stripper consisting of nitrogen springs, which are hollow cylinders containing compressed nitrogen gas.

preloading

The intentional compression of a spring before it is used in an operation.

spring

A device that yields under a compressive force and returns to its original shape once the force is removed.

stripper bolt

A bolt used to attach the stripper plate to the upper or lower die shoe. Mechanical springs may be fitted over the stripper bolt.

stripper plate

The metal plate that contacts the sheet to strip it from the punch. Stripper plates are commonly made from steel.

stripper system

The assembled components within a die set responsible for stripping the stock from the punch as it retracts.

urethane stripper

A stripper consisting of a hollow, cylindrical spring made from urethane rubber. The urethane spring bulges under compressive force.

 


 

Coil Loading Procedure:

 

 

Term

Definition

bridge grip feeder

A type of grip feeder that clamps stock in the center or across its entire width.

butt-welding

Welding a joint by fastening its ends together without overlapping.

camber

A coil material defect in which one edge of the material is longer than the other.

cascade rolls

Non-powered rolls at the end of some coil line components that form a waterfall shape and keep material from kinking as it enters and exits the equipment.

c-hook

A lifting tool shaped like the letter "C," which is attached to a lifting device and grabs the coil for loading onto the uncoiler.

clockspringing

A type of coil defect in which the coil wraps separate from one another and spread around the diameter of the coil.

coil break

A coil material defect in which the material has a series of evenly spaced lines across its surface. Coil break may result in an unacceptable surface finish on parts.

coil grab

A lifting tool attached to a lifting device, which grabs the coil's outer diameter with tongs or other types of gripping mechanisms and loads the coil onto the uncoiler.

coil set

The natural curvature remaining in coil after it has been unwound.

coil stock

A long, thin sheet of metal that has been wound tightly. Stock first appears as coil for many press operations.

confining plates

Plates on a cradle uncoiler, which keep the coil stock centered in the cradle.

cradle

A type of uncoiler that supports coil from below on its outside diameter.

crossbow

The curvature of the coil stock across its width. The center of coil stock with crossbow is higher than the edges.

debanding

Removing the retaining bands from the outside diameter of the coil stock.

die area

The area that contains the die. Press operators should enter the die area only with approved handling tools.

die starting position

A line or arrow marked on the die that indicates where the coil stock should be lined up before production begins.

edge wave

A coil material defect in which the edges appear scalloped. Edge wave is often caused by pinch roll pressure in the cradle, straightener, or feed.

elliptical

Having an oval shape. Coil that has an elliptical inside diameter is known as squatting.

entrance pinch rolls

Pinch rolls located at the start of the straightener, which provide the power necessary to thread material into the straightening rolls.

exit pinch rolls

Pinch rolls located at the end of the straightener, which assist the straightening rolls during production.

feed clamping bar

A bar located on a bridge grip feeder, which holds down the coil stock as it enters the grip feeder.

feed clamping piston

A clamping device on an open-throat grip feeder, which applies air pressure to the coil stock as it enters the grip feeder.

flywheel

The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram.

grip feeder

A type of feed mechanism that uses one stationary and one sliding clamping mechanism to intermittently feed stock into the press.

hardness

The ability of a material to resist scratching or penetration.

hold-down arm

A device usually found on a reel that applies pressure on the coil and keeps it from expanding.

idler rolls

An unpowered component on a straightener that bends stock as it passes through the equipment. Idler rolls are positioned above the stock.

inch mode

A mode of press operation in which the ram moves intermittently at different points in the stroke. Inch mode is most often used during die setup and before loading a new coil.

inside diameter

An interior cylindrical surface of a hole.

keepers

A component on a reel uncoiler that prevents the coil from sliding off the mandrels.

lifting device

A device that carries the coil stock to the uncoiler. The lifting device may be a crane, hoist, or forklift.

lifting tool

A device that picks up the coil and places it on the uncoiler. Common lifting tools consist of slings, c-hooks, and coil grabs.

loop control device

A device that detects when stock must be advanced to maintain the slack loop. Either a powered uncoiler or straightener will typically have a loop control device.

mandrel

A component on a reel uncoiler that holds coil through its inside diameter. Mandrels expand to hold the coil in place.

open-throat grip feeder

A type of grip feeder that clamps stock on one edge. Open-throat grip feeders can accommodate wider stock.

outside diameter

An exterior cylindrical surface of a part or stock.

pallet decoiler

A type of uncoiler in which the coil stock is placed on a horizontal table and unwound horizontally.

photoelectric sensors

A type of sensor on the press that emits an electric beam. When the beam is interrupted, the sensor sends a signal to the press to stop the operation.

pilot hole

The hole in the strip that aligns with the pilot pin. As the ram nears the bottom of the stroke, the pilot pins must enter their pilot holes.

pilot pin

A long, slender punch with a rounded tip used to position the metal sheet by entering a previously formed hole.

pinch rolls

A component on a cradle uncoiler that assists uncoiling by pulling on the stock.

press operator

The person who operates and monitors the stamping press during production.

ram

The main upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the ram.

reel

A type of uncoiler that holds coil by its inside diameter and suspends it above the ground.

rest rolls

A component on a cradle uncoiler that supports the coil and rotates to unwind the coil.

restrictor

A device that holds down coil stock in the uncoiler device to minimize clockspringing.

retaining bands

Bands wrapped around the coil stock to keep the coil tightly wound. The press operator clips the retaining bands once the coil is loaded on the uncoiler.

roll feeder

A type of feed mechanism that uses rotating rolls to intermittently feed stock into the press.

slack loop

Excess stock that hangs between coil-line equipment. The slack loop allows continuous and intermittent equipment to work together.

sling

A loop of material, which picks up coil stock and places it on the uncoiler. Slings can be made of chain, wire, or nylon.

slug

The discarded section of metal resulting from a punching or piercing operation.

spindle

A rotating shaft on a reel uncoiler, which turns mandrel arms.

squatting

A type of coil defect in which the coil appears egg-shaped. The inside diameter of squatting coil is elliptical instead of round.

stock guides

A device used to direct strip through the die.

straightener

A mechanism designed to repeatedly bend stock back and forth to remove any natural curvature.

straightening rolls

A powered component on a straightener that bends and passes stock through the equipment. Straightening rolls are positioned below the stock.

telescoping

A type of coil defect in which the coil wraps protrude from the side of the coil.

temper

To strengthen or harden metal by a heating it or heating then cooling it.

threading table

A flat table that bridges the gap between the straightener and the feed mechanism.

top dead center

The highest position in the ram's stroke. TDC is also referred to as stroke-up position.

uncoiler

A mechanism designed to hold coil and gradually unwind it during press operations.

wedge

A type of pivoting clamp attached to the c-hook's carrying arm that allows the c-hook to turn the coil from a horizontal position to a vertical position for loading onto the uncoiler.

 


 

Die Setting Procedures:

 

 

Term

Definition

adjustment rod

A rod located on the press that is periodically adjusted during die setting to allow for adjusting the shut height.

air cushion

An air-actuated press accessory that is placed below or inside a bolster plate or die block, which is used to increase pressure on the die using pressure pins. The air cushion can also be used to lift the part out of the die.

bolster

A plate that is designed to hold the lower die shoe in place. The bolster plate is attached to the top surface of the press bed.

bolt head

The top portion of a bolt.

bottom dead center

The lowest position in the ram's stroke. BDC is also referred to as stroke-down position.

bracket

An overhanging object that is designed to support another object.

bridge

A part of the clamp through which a bolt passes to secure the die on the bolster or slide face. One side of the bridge rests on the die shoe and the other rests on the fulcrum block.

burr

Any type of chip or scrap on a surface that is considered an imperfection.

capacity

The maximum amount of force that a press can exert.

clamp

A device that usually consists of a bridge, bolt, and a fulcrum block, which is used to secure the die set to the press.

counterbalance air pressure

A setting on the press that correctly counterbalances the weight of the slide and its attachments so that the press exerts the proper amount of pressure.

die assembly

The collective assembly of upper and lower die shoes, guide pins and bushings, and punch and die retainers.

die clamp

A workholding device that maintains the position of the die by holding it in place.

die lifter

A device located in the bed of the press that lifts the die assembly up so that fork lifts can get under the die assembly and easily lift it out of the press.

die setter

An individual who installs the die in the stamping press.

electric slide adjust button

A feature on some types of presses that allows the press operator to adjust shut height electronically.

feeler gauge

A device sometimes used in stamping to determine if there is proper clearance between the punch and die components.

flywheel

The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram. The flywheel moves in a circular motion; the pitman converts this circular motion to an up-and-down motion.

fulcrum

A device used to precisely align the bridge with the slot in the bolster. The fulcrum block can either be two interlocking triangles or one square.

guide pin

A fixed pin or post that is located in the lower shoe and fitted to bushings in the upper shoe that ensures precise alignment of the upper die shoe and lower die shoe.

hold-down bolt

Another name for a lock-down bolt.

inner diameter

The interior surface of a hole in a workpiece or tooling.

knockout bar

A device used to assist in ejecting parts from the die.

locknut

A type of nut that is used to install the die. Locknuts have their name because they lock down on the part.

lockout

A safety procedure required by OSHA that takes steps to dissipate all stored power during maintenance work. Never try to operate a machine that is under lockout.

machine bolt

A threaded bolt. A machine bolt does not have the same bolt head as a t-bolt and must never be placed in a t-slot.

model number

A number that identifies the style of press with which you are working.

operator control

The controls on the press that, when depressed, cause the press to cycle. Operator controls often contain safety devices that prevent the press from cycling accidentally.

outer diameter

The exterior surface of a shaft in a workpiece or tooling.

parallels

Two pieces of steel that are the same thickness and either sit on or get bolted to the upper die shoe to achieve proper shut height for the press.

pitman

The device that links the crankshaft to the ram. The pitman converts the circular motion of the flywheel into up-and-down motion for stamping.

press operator

An individual who operates and monitors the stamping press during production.

press specification plate

A plate attached to the side or back of the stamping press that identifies important information about that specific press.

pressure pin

A pin used in conjunction with an air cushion that transfers pressure from the air cushion to the bottom of the die.

punch shank

A device used to clamp the punch die shoe into the ram face.

quick die change positioning locator

A device that centers the new die in the press if the new die is the same width as the previous die. Ususally more than one quick die change positioning locator is used.

ram

The main upper portion of the press that slides up and down within the press frame during operation.

rough adjust

A term used to describe the initial adjusting of the shut height of the press.

safety block

A device used during press maintenance. The safety block is placed in the die area to ensure that the press cannot accidentally stroke down.

safety plug

A plug on the press in which the safety block is inserted. When the safety block is not plugged into the safety plug, the press is disabled.

serial number

A number that identifies the specific press with which you are working.

shank

A device located on the die set that ensures that the part does not stick to the upper half of the die. A shank can also be used to clamp the upper half of the die to the press.

shedder plate

A pin, rod, or plate, operated by mechanical means that ejects blanks, parts, or scrap from the die.

shut height

The distance from the slide face to the bolster when the slide is at bottom dead center.

shut height adjustment readout

Either a mechanical or electrical device on the press that indicates how much the shut height was adjusted.

slide face

The surface on the press that comes into contact with the upper die set.

slide hole

A hole in the ram face into which the shank on the punch die is inserted. A collar is placed on the shank so that it does not come out of the slide hole.

spring-loaded pin

A pin used in conjunction with springs to transfer pressure from the springs to the bottom of the die.

standardized tooling

Any of various types of tooling used universally. Types of standardized tooling vary only slightly in their dimensions.

stop block

A block or blocks that are normally located near each guide pin to ensure that the press does not close too far. Stop blocks can also determine the correct shut height adjustment.

striker mechanism

An adjustable switch that activates an air-operated valve and controls automation.

stroke length

A measurement from bottom dead center to top dead center that indicates how far the press opens during a stamping operation.

strokes per minute

The amount of times that a press strokes down in one minute.

tapped hole

A hole with internal threads cut by a drill-like tool called a tap.

t-bolt

A type of bolt that has a "T" shaped head. T-bolts slide into t-slots.

top dead center

The highest position in the ram's stroke. TDC is also referred to as stroke-up position.

t-slot

A space in the shape of a "T" sometimes located in the bolster and the slide face. Matching t-bolts are slid into the t-slot.

washer

A flat metal disc used beneath a nut or axle bearing or a joint to relieve friction, prevent leakage, or distribute pressure.

weight-to-air pressure plate

A plate attached to the side or back of the stamping press that provides air pressure settings for various upper die weights. The weight-to-air pressure plate is important when setting the counterbalance air pressure.