Unlocking the Press Room Code
Every field has its secret language, and the press room is no exception. Understanding these terms is your key to confidently explore stamping presses, die-cutters, and other essential equipment for your press room.
Whether you’re a seasoned buyer or just embarking on your search, PRI's application engineers have curated the essential vocabulary you need to shop for the press equipment you need to drive efficient production and take your manufacturing game to new heights.
Bookmark this page as a handy reference guide!
Term | Definition |
Bed | The stationary portion or "table" of the press to which the bolster is attached. Press Rigidity is critical to the lower maintenance and increases die life. |
Blanking | Blanks are produced from the shearing or cutting of outside contours or shapes out of sheet or strip stock. For larger production runs, blanking is often done in multiple dies, and is combined with other operations such as piercing and forming in combination and progressive dies. |
Bolster Plate | A plate or block attached to the top of the press bed where the die is fastened. In some rare cases the die is fastened directly to the bed. The bolster can be machined for application specifics or standard TSlot for Quick Die Changing. |
Brake | The friction mechanism is used to stop or control the motion of a press, feed, or other mechanism. |
Capacity | Rated press capacity is the tonnage pressure the slide can safely exert at the bottom of the stroke. Mechanical press capacity is typically based on the bending capacity of the main shaft (crank, toggle, or eccentric shaft). It is important to know and understand: 1. tonnage Curve based on rating point ABDC above bottom dead center and 2. Energy Curve based on press speeds. Presses should only be used within the designed capacity. |
Clutch | A coupling used to connect or disconnect a driving machinemember, such as a shaft or wheel, to or from a driven machinemember, such as another wheel or shaft. The engaging or disengaging can be done by hand operated controlling device operated manually or automatically. |
The most popular method of coil feeding a press is with a servo drive coil feeder mounted to the press near the incoming side of the die set. Complete systems are available from coil loading, unwinding, straightening, lubricating servo feeding material into the die. | |
Coining | A squeezing operation, usually performed in a closed die in which the metal is forced to flow and fill the shape and profile of the die. There is a definite change in metal thickness. |
Counterbalance | An air driven system made up of cylinders that can equalize the weight of the upper Slide and the additional weight of the upper die that is mounted to the slide. It is important to have this adjusted correctly based on upper die weight and speed of press to prevent damage to press connections points. |
Crimping | An operation in which the open end of a can or shell is forced tight or around a mating part. This type of work is limited largely to assembly operations. |
Curling | The forming of an edge having a circular cross section along a sheet or around the end of a shell or tube. This operation is sometimes called false wiring. |
Deep Drawing | Forming of deep recessed parts from sheet material by means of a plastic flow of the material worked in presses and dies. |
Deflection | The amount of bending or the deviation from a straight line or a plane when a force or load is applied to a surface of a machine member or part. |
Die | 1. A tool used on a press for any operation or series of operations, such as forming, drawing, piercing and cutting. The upper member (or members) are attached to the slide (slides) of the press, with the lower member clamped or bolted to the bed or bolster, shaped so that the material placed between them is cut or formed when the press makes a stroke.
2. The female part of a complete die assembly as described in (1).
3. A tool for cutting external threads. |
Die Cushion | An attachment or press accessory which gives additional motion or pressure required in many compound press operations. The pressure medium can be rubber, springs, air or liquid (usually oil). Air (pneumatic) cushions are the most commonly used. Uses include blank holding, drawing, maintaining uniform pressure on a die part, knockout and stripping. Typically mounted in order on the press bed, they can sometimes be mounted on top of a press slide flange. |
Die Height | The closed height of a die during the working portion of the press or completed operation in the die. Die Height is measured from the top of the bolster plate to the bottom of the slide. |
Optional Electronics in our control can offer in groups of 8, monitoring of events at various portions of the stroke. | |
Eccentric | Essentially a dick arranged to rotate around a center, not the center of dish parallel to it. An eccentric should crank with crankpin of such size that it contains or surrounds the shaft. The eccentric with its strap or connection is used in the eccentric press and for driving auxiliary attachments, such as lift outs and various types of feeds. |
Embossing | A process for producing raised or sunken designs in sheet metal by means of a male and female die. |
Extrusion | A process in which pressure is applied to a slug of metal causing the metal to flow either up around the punch (toothpaste tubes) or down in the direction of pressure (cartridge cases - Hooker process). |
Fine Blanking | Fine blanking is a specialized form of blanking where there is no fracture zone when shearing. This is achieved by compressing the whole part and then an upper and lower punch extract the blank. This allows the process to hold very tight tolerances, and perhaps eliminate secondary operations. |
Flywheel | A wheel used on an engine or machine with a rotation energy or inertia able to prevent excessive or sudden changes in speed. In modern mechanical presses the flywheel is usually belted, chained or geared to the driving motor. A clutch is mounted on or within the flywheel. |
Flywheel Break | An air cylinder with electric controlled solenoid that has the ability to stop the rotation of the flywheel. This safety device should be engaged before entering die area. |
Gibs | Guides or shoes that ensure the proper sliding fit between two machine parts and which usually are adjustable for taking up excessive wear, e.g. press gibs the guide the press slide. |
Inching | A machine control process used to adjust and set dies and other tools in by precisely controlling the working member of the press in short increments usually by rapidly engaging and disengaging the clutch or using electric or pneumatic push buttons. |
Ironing | A process in which the wall thickness of the shell is reduced without changing the O.D. of the shell (cartridge casework for example). |
Knuckle Joint | A unique press drive system with a hinged pin that is well suited for coining, extruding and embossing work. |
Lancing | Slitting and forming a pocket shaped opening in sheet metal, without removing metal. |
Link Motion | A modified slide motion that produces either constant velocity or increased slow down through the working part of the press stock. |
Link Moton | A modified slide motion that produces either constant velocity or increased slow down through the working part of the press stroke. |
Overload | Hydraulic Overload Protection is a pressurized cavity located under the connection point in the slide. This system is designed to protect the press from exceeding 110% of press capacity. It can also be used for freeing stuck dies bottom dead center. (BDC) |
Piercing | A general term for cutting (shearing or punching) openings, such as holes and slots in sheet material, plate, or parts. Like blanking, the slug or piece produced by piercing is scrap, whereas the blank produced blanking is the useful part. In both cases the burr is opposite. |
Pitman | A connecting rod to convey motion and pressure from a revolving crank of eccentric to a sliding or swinging member, such as a slide or lever. A press connecting rod. |
Plunger Guide | A superior connection compared to pitman or connecting rod. Plunger Gilded presses delivery tonnage vertically to slide eliminating side thrust loads into slide gibs and tooling. |
Pneumatic Die Cushions | Pneumatic (air) attachment consisting essentially of cylinder piston, pressure plate and accessories generally used with a press for clamping, blank holding or ejection. |
Progressive Dies | A series of two or more dies arranged in line for performing two or more operations on a part, one operation (single or compound) performed in each die, at each station. Work in the form of a strip is usually fed to progressive dies automatically by a roll feed. |
Optional systems can be provided that decreases the upper and lower die clamping time. Normally consists of Air over Hydraulic Tank and ump units that controls hydraulically powered clamps on the slide and bolster. | |
Redrawing | The second operation that follows deepdrawing operations, in which cups are deepened and reduced in cross section. |
Reverse Tonnage | The most common name for Snap Thru Tonnage which occurs mostly during blanking operations. When the material is 80% complete in the cutting process, the energy that is released when the break thru occurs can be very violent and cause excessive vibration to the press and tooling. Solutions are available. |
Shut Height Die Height | The shut height of an upright press is the distance from the top of the bed to the bottom of the slide with stroke down and adjustment up. The shut height must always be defined either from the top of the bed or from the top of the bolster. The shut height of a horizonal or inverted press, or of a press with adjustable bed, can be defined in a similar manner. Generally, the shut height is equal to the maximum dieheight of the die that can be accommodated, taking the bolster into consideration. Die height is measured the same but to the top of the bolster. |
Slide | The most common name for the main reciprocating member of a press, guided in the press frame and to which the punch or upper die is fastened. It is also referred to as the ram. The inner slide of a double action press is called the plunger; the outer slide of a double action press is called the blank holder slide, and the slide of a hydraulic press is often called the platen. |
Slide Adjustment Device | A motorized system with worm shaft and worm gear that allows the Die Height to be changed via a push button. This system also comes with a digital readout. |
Slide Locking device | Hydraulic Slide Adjustment locking device prevents slide creep up under heavy stamping loads. |
Staking | An operation in which two or more parts are assembled permanently by upsetting a small portion of metal over the mating part, causing compression on the assembled parts. |
Stamping | A manufacturing process by which sheets or strips of material are punched using a machine press or stamping press to form the sheet. This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part or could occur through a series of stages. The process is usually carried out on sheet metal but can also be used on other materials, such as polystyrene. |
Stroke | The reciprocating motion of a press slide, usually specified as the number of inches between the terminal points of the motion. |
Swaging | Forming a metal by the rapid striking of a large number of successive blows. In the case of aircraft cable fittings, the fitting is rotated while the press blows are being struck. |
Throat (gap) | The open space in a gap frame press back of the slide centerline. The depth of the throat (gap) is the distance from the slide centerline back to the frame metal of the upright section. |
Tie Rod | Four long rods, with threads and nuts on both ends, which hold the frame members of a straightside press together. These rods are stretched to place the frame members under compressive load. |
Automation system that can move parts from station to station or die to die to make multiple hits and form parts. | |
Trimming | A secondary operation on drawn or formed parts to remove excess metal on the flange or axial length. |