Vocabulary 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.