Blanking

A cutting operation where the punched-out piece (the blank) is the desired part. The surrounding material is scrap.

Piercing

A cutting operation where a hole is punched into the workpiece. The punched-out piece is scrap (slug), and the remaining strip is the part.

Punching

Often used interchangeably with piercing, but can refer to the general act of creating a hole.

Bending

The process of deforming metal around a straight axis to create an angle.

Forming

A general term for any operation that changes the shape of the metal without cutting or shearing, including bending, drawing, and flanging.

Drawing

A forming operation where a punch forces a blank into a die cavity to create a deep, three-dimensional shape (e.g., a cup). The metal thickness changes as it flows.

Stretching

A forming operation where the surface area of the metal increases, thinning the material as it is stretched over a form.

Coining

A high-precision compression operation that squeezes metal within a closed die to imprint fine details or achieve critical dimensions. Minimal material flow occurs.

Embossing

A process that creates raised or recessed designs, lettering, or ribs in the material to add stiffness or for decorative purposes.

Notching

Cutting a portion of material from the edge of a workpiece.

Lancing

Making a partial cut and bending the material to create a feature like a vent, louver, or tab without separating any material from the strip.

Trimming

Cutting away excess or irregular flash from a drawn or formed part to finalize its profile.

Shaving

A secondary cutting operation that removes a small amount of material from a previously cut edge to achieve a smoother finish and tighter tolerance.

Die

The entire tooling assembly used in a press to cut or form metal. It consists of a Punch (upper, male part) and a Die (lower, female part).

Punch

The hardened tool steel component that is mounted on the press ram and moves into the stationary die to perform the operation.

Die Set

A standardized assembly that includes guide pins (or pillars) and bushings to ensure precise alignment between the upper and lower halves of the tool.

Progressive Die

A die with multiple stations. A metal strip feeds through it, and a different operation is performed at each station with each press stroke. A finished part is cut off at the final station.

Compound Die

A die that performs multiple operations (e.g., blanking and piercing) in a single station with one stroke of the press.

Transfer Die

A system where an individual blank is mechanically moved (transferred) from one station to the next within a single press for secondary operations.

Pilot

A precision pin in the die that enters a previously pierced hole to accurately position the strip for the next operation in a progressive die.

Stripper Plate

A plate that holds the material strip down, preventing it from sticking to the punch as it retracts.

Knockout

A mechanism inside the die that pushes the finished part or slug out of the die cavity.

Nitrogen Cylinder / Gas Spring

A component used within the die to provide a strong, consistent force for actions like lifting the stripper plate or actuating pads.

Coil

A continuous roll of sheet metal that is fed into a progressive die press.

Blank

A flat piece of sheet metal, either cut from a coil or sheet, that is ready for forming.

Strip

The continuous piece of metal, often from a coil, that is fed through a progressive die.

Temper

The hardness and strength of the metal (e.g., H32, O-temper).

Grain Direction

The directional alignment of the metal's crystalline structure resulting from the rolling process. It affects formability, especially in bending.

Burr

A sharp, rough edge of material that remains on the workpiece after a cutting or shearing operation.

Deburring

The process of removing burrs to create a safe, smooth edge.

Slug

The small piece of scrap material punched out to create a hole.

Web

The thin, flat section of material that connects features in a strip layout; often the area where the part is attached to the carrier strip before being cut free.

Carrier Strip

The portion of the strip that conveys the partially formed parts through the progressive die.

Parting Line

The line on a stamped part that corresponds to where the punch and die meet.

Bend Radius

The inside radius of a bend.

Bend Allowance (BA)

The length of the neutral axis (the part that doesn't stretch or compress) between the bend lines. Used to calculate the flat pattern length.

Bend Deduction (BD)

The amount of material to be subtracted from the sum of the two flanges to get the correct flat pattern length.

K-Factor

A ratio used to calculate the bend allowance. It represents the location of the neutral axis in the material thickness.

Springback

The elastic recovery of the metal after bending, causing the final bend angle to be slightly more open than the angle in the die. The die must be designed to overbend to compensate.

Neutral Axis

The plane within the material that experiences neither compression nor tension during bending.

Warpage/Twisting

Distortion of the part after stamping, often caused by residual stresses or uneven material flow.

Wrinkling

A defect occurring in drawing or stretching where the metal buckles or forms wrinkles due to excessive compressive stresses.

Tearing / Splitting

A crack or rupture in the material caused by being stretched beyond its formability limits.

Die Mar / Scratch

A surface scratch on the part caused by contact with the tooling.

Gallling

A condition where the workpiece material adheres (welds) to the tooling surface due to friction and pressure.