A die is a specialized
machine tool
A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All m ...
used in
manufacturing industries
Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to a range ...
to cut and/or
form
Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens.
Form also refers to:
*Form (document), a document (printed or electronic) with spaces in which to write or enter data
...
material to a desired shape or profile.
Stamping dies are used with a
press
Press may refer to:
Media
* Print media or news media, commonly called "the press"
* Printing press, commonly called "the press"
* Press (newspaper), a list of newspapers
* Press TV, an Iranian television network
People
* Press (surname), a fam ...
,
as opposed to
drawing dies (used in the manufacture of wire) and
casting dies (used in
molding) which are not. Like molds, dies are generally customized to the item they are used to create.
Products made with dies range from simple
paper clip
A paper clip (or paperclip) is a tool used to hold sheets of paper together, usually made of steel wire bent to a looped shape (though some are covered in plastic). Most paper clips are variations of the ''Gem'' type introduced in the 1890s or e ...
s to complex pieces used in advanced technology.
Continuous-feed laser cutting
Laser cutting is a technology that uses a laser to vaporize materials, resulting in a cut edge. While typically used for industrial manufacturing applications, it is now used by schools, small businesses, architecture, and hobbyists. Laser cutt ...
may displace the analogous die-based process in the automotive industry, among others.
Die stamping
Blanking and piercing
Blanking and piercing are shearing processes in which a punch and die are used to produce parts from coil or sheet stock. Blanking produces the outside features of the component, while piercing produces internal holes or shapes. The web is cre ...
are two
die cutting operations, and
bending
In applied mechanics, bending (also known as flexure) characterizes the behavior of a slender structural element subjected to an external load applied perpendicularly to a longitudinal axis of the element.
The structural element is assumed to ...
is an example of a die forming operation.
Die forming
Forming operations work by deforming materials like
sheet metal
Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes.
Thicknesses can vary significantly; ex ...
or plastic using force (
compression
Compression may refer to:
Physical science
*Compression (physics), size reduction due to forces
*Compression member, a structural element such as a column
*Compressibility, susceptibility to compression
* Gas compression
*Compression ratio, of a ...
,
tension
Tension may refer to:
Science
* Psychological stress
* Tension (physics), a force related to the stretching of an object (the opposite of compression)
* Tension (geology), a stress which stretches rocks in two opposite directions
* Voltage or el ...
, or both) and rely on the material's
mechanical properties
A materials property is an intensive property of a material, i.e., a physical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another ca ...
. Forming dies are typically made by
tool and die makers and put into production after mounting into a
press
Press may refer to:
Media
* Print media or news media, commonly called "the press"
* Printing press, commonly called "the press"
* Press (newspaper), a list of newspapers
* Press TV, an Iranian television network
People
* Press (surname), a fam ...
.
Differences between materials
For the
vacuum forming
Vacuum forming is a simplified version of thermoforming, where a sheet of plastic (in various forms HIPS (High impact polystyrene) for low impact products, or for Bathroom shower trays ABS, and exterior vehicle parts HDPE, plus various other ty ...
of plastic sheet only a single form is used, typically to form transparent plastic containers (called
blister packs
A blister pack is any of several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals.
The primary component of a blister pack is a cavity or pocket made from a formable web, usually a thermofor ...
) for merchandise. Vacuum forming is considered a simple
molding thermoforming
Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and cert ...
process but uses the same principles as die forming.
For the forming of sheet metal, such as
automobile
A car or automobile is a motor vehicle with Wheel, wheels. Most definitions of ''cars'' say that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, pe ...
body parts, two parts may be used: one, called the ''punch'', performs the stretching, bending, and/or blanking operation, while another part that is called the ''die block'' securely clamps the workpiece and provides similar stretching, bending, and/or blanking operation. The workpiece may pass through several stages using different tools or operations to obtain the final form. In the case of an automotive component, there will usually be a shearing operation after the main forming is done. Additional crimping or rolling operations may be performed to ensure that all sharp edges are hidden and/or to add rigidity to the panel.
Die components
The main components of a die set (including press mounting) are as follows. Note that because
nomenclature
Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal naming conventions, conventions of everyday speech to the i ...
varies between sources, alternate names are in parenthesis:
* Die shoes (holders) – the set of flat, parallel plates that serve as the foundation for mounting die components.
* Guide pins (pillars) – together with guide bushings, the pins align the die shoes precisely during each press stroke.
*Die set (plates).
''Note: placement can be inverted depending on the operation, such as use of a knock-out:''
** Die block – the lower (bottom) half of the die set. Machined to conform to the desired shape of the workpiece being formed or cut.
**Punch plate – the upper (top) half of the die set. Holds and supports the different punches in place.
*Punch – male portion of the die which punches through the sheet metal and into the corresponding (female) section of the die block. More specifically:
**Blanking punch – performs a dual-purpose operation where either a profiled slug, called the blank, is cut out and used for further working, or where a finished piece is cut free from the sheet metal.
**Pierce punch – cuts a desired shape (circular,
polygon
In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed ''polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two toge ...
al, etc.) out of the workpiece. The slug is discarded.
*Stripper plate (pad) – spring-loaded plate that separates (i.e., strips) the workpiece from the withdrawing punch after each press stroke.
*Pilot – This will help to place the sheet accurately for the next stage of operation.
*Stock guide – ensures that the material being worked on always goes in the same position, within the die, as the last one.
*Setting (stop) block – This part is used to control the depth that the punch goes into the die.
*Shank – installs the punch plate to the press. It should be aligned and situated at the center of gravity of the plate.
Process
*Blanking: A blanking die produces a flat piece of material by cutting the desired shape in one operation. The finished part is referred to as a blank. Generally a blanking die may only cut the outside contour of a part, often used for parts with no internal features.
Three benefits to die blanking are:
#''Accuracy''. A properly sharpened die, with the correct amount of clearance between the punch and die, will produce a part that holds close dimensional tolerances in relationship to the part's edges.
#''Appearance''. Since the part is blanked in one operation, the finish edges of the part produces a uniform appearance as opposed to varying degrees of burnishing from multiple operations.
#''Flatness''. Due to the even compression of the blanking process, the end result is a flat part that may retain a specific level of flatness for additional manufacturing operations.
*
Broaching
The BROACH warhead is a Tandem-charge, multi-stage warhead developed by Team BROACH; BAE Systems Global Combat Systems Munitions, Thales Missile Electronics and QinetiQ. BROACH stands for ''Bomb Royal Ordnance Augmented CHarge''.
Development of ...
: The process of removing material through the use of multiple cutting teeth, with each tooth cutting behind the other. A broaching die is often used to remove material from parts that are too thick for shaving.
*Bulging: A bulging die expands the closed end of tube through the use of two types of bulging dies. Similar to the way a chef's hat bulges out at the top from the cylindrical band around the chef's head.
#Bulging fluid dies: Uses water or oil as a vehicle to expand the part.
#Bulging rubber dies: Uses a rubber pad or block under pressure to move the wall of a workpiece.
*
Coining: is similar to forming with the main difference being that a
coining die may form completely different features on either face of the blank, these features being transferred from the face of the punch or die respectively. The coining die and punch flow the metal by squeezing the blank within a confined area, instead of bending the blank. For example, an Olympic medal that was formed from a coining die may have a flat surface on the back and a raised feature on the front. If the medal was formed (or embossed), the surface on the back would be the reverse image of the front.
*Compound operations: Compound dies perform multiple operations on the part. The compound operation is the act of implementing more than one operation during the
press
Press may refer to:
Media
* Print media or news media, commonly called "the press"
* Printing press, commonly called "the press"
* Press (newspaper), a list of newspapers
* Press TV, an Iranian television network
People
* Press (surname), a fam ...
cycle.
*Compound die: A type of die that has the die block (matrix) mounted on a punch plate with perforators in the upper die with the inner punch mounted in the lower die set. An inverted type of blanking dies that punches upwards, leaving the part sitting on the lower punch (after being shed from the upper matrix on the press return stroke) instead of blanking the part through. A compound die allows the cutting of internal and external part features on a single press stroke.
*
Curling
Curling is a sport in which players slide stones on a sheet of ice toward a target area which is segmented into four concentric circles. It is related to bowls, boules, and shuffleboard. Two teams, each with four players, take turns sliding ...
: The curling operation is used to roll the material into a curved shape. A door hinge is an example of a part created by a curling die.
*Cut off: Cut off dies are used to cut off excess material from a finished end of a part or to cut off a predetermined length of material strip for additional operations.
*
Drawing
Drawing is a form of visual art in which an artist uses instruments to mark paper or other two-dimensional surface. Drawing instruments include graphite pencils, pen and ink, various kinds of paints, inked brushes, colored pencils, crayons, ...
: The drawing operation is very similar to the forming operation except that the drawing operation undergoes severe
plastic deformation
In engineering, deformation refers to the change in size or shape of an object. ''Displacements'' are the ''absolute'' change in position of a point on the object. Deflection is the relative change in external displacements on an object. Strain ...
and the material of the part extends around the sides. A metal cup with a detailed feature at the bottom is an example of the difference between formed and drawn. The bottom of the cup was formed while the sides were drawn.
*Extruding: Extruding is the act of severely deforming blanks of metal called slugs into finished parts such as an
aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...
I-beam
An I-beam, also known as H-beam (for universal column, UC), w-beam (for "wide flange"), universal beam (UB), rolled steel joist (RSJ), or double-T (especially in Polish language, Polish, Bulgarian language, Bulgarian, Spanish language, Spanish ...
. Extrusion dies use extremely high pressure from the punch to squeeze the metal out into the desired form. The difference between cold forming and extrusion is extruded parts do not take shape of the punch.
*Forming: Forming dies to bend the blank along a curved surface. An example of a part that has been formed would be the positive end(+) of a AA battery.
*Cold forming (cold heading): Cold forming is similar to extruding in that it squeezes the blank material but cold forming uses the punch and the die to create the desired form, extruding does not.
*
Roll forming
Roll forming, also spelled roll-forming or rollforming, is a type of rolling involving the continuous bending of a long strip of sheet metal (typically coiled steel) into a desired cross-section. The strip passes through sets of rolls mounted on ...
: a continuous bending operation in which sheet or strip metal is gradually formed in tandem sets of rollers until the desired cross-sectional configuration is obtained. Roll forming is ideal for producing parts with long lengths or in large quantities.
*Horning: A horning die provides an arbor or horn in which the parts are placed for secondary operations.
*
Hydroforming
Hydroforming is a cost-effective way of shaping ductile metals such as aluminium, brass, low alloy steel, and stainless steel into lightweight, structurally stiff and strong pieces. One of the largest applications of hydroforming is the automot ...
: Forming of tubular part from simpler tubes with high water pressure.
*
Pancake die
A pancake die is a simple type of manufacturing die that performs blanking or piercing. Many dies perform complex procedures simultaneously (or progressively for progressive die) such as coining, piercing, forming, bending in addition to produc ...
: A Pancake die is a simple type of manufacturing die that performs blanking and/or piercing. While many dies perform complex procedures simultaneously, a pancake die may only perform one simple procedure with the finished product being removed by hand.
*Piercing: The piercing operation is used to pierce holes in stampings.
*
Transfer die: Transfer dies provide different stations for operations to be performed. A common practice is to move the material through the die so it is progressively modified at each station until the final operation ejects a finished part.
*Progressive die: The sheet metal is fed through as a coil strip, and a different operation (such as punching, blanking, and notching) is performed at the same station of the machine with each stroke of a series of punches.
*
Punching
Punching is a forming process that uses a punch press to force a tool, called a ''punch'', through the workpiece to create a hole via shearing. Punching is applicable to a wide variety of materials that come in sheet form, including sheet meta ...
:
*Shaving: The shaving operation removes a small amount of material from the edges of the part to improve the edges finish or part accuracy. (Compare to Trimming).
*Side cam die: Side cams transform vertical motion from the press ram into horizontal or angular motion.
*Sub press operation: Sub-press dies blank and/or form small watch, clock, and instrument parts.
*
Swaging
Swaging () is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process, but also may be hot worked.
The term swage may apply to the process (verb) o ...
: Swaging (necking) is the process of "necking down" a feature on a part. Swaging is the opposite of bulging as it reduces the size of the part. The end of a
shell casing
A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile ( bullet, shot, or slug), a propellant substance (usually either smokeless powder or black powder) and an ignition device ( primer) within a metall ...
that captures the bullet is an example of swaging.
*Trimming: Trimming dies cut away excess or unwanted irregular features from a part, they are usually the last operation performed.
*Pillar set: Pillar set are used for alignment of dies in press movement.
Steel-rule die
''Steel-rule'' die, also known as ''cookie cutter'' dies, are used for cutting sheet metal and softer materials, such as plastics, wood,
cork
Cork or CORK may refer to:
Materials
* Cork (material), an impermeable buoyant plant product
** Cork (plug), a cylindrical or conical object used to seal a container
***Wine cork
Places Ireland
* Cork (city)
** Metropolitan Cork, also known as G ...
,
felt
Felt is a textile material that is produced by matting, condensing and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood ...
,
fabric
Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...
s, and
paperboard
Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.30 mm, 0.012 in, or 12 Inch#equivalences, points) than paper and has certain ...
. The cutting surface of the die is the edge of hardened steel strips, known as ''steel rule''. These steel rules are usually located using saw or laser-cut grooves in
plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...
. The mating die can be a flat piece of
hardwood
Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...
or steel, a male shape that matches the workpiece profile, or it can have a matching groove that allows the rule to nest into. Rubber strips are wedged in with the steel rule to act as the stripper plate; the rubber compresses on the down-stroke and on the up-stroke it pushes the workpiece out of the die. The main advantage of steel-rule dies is the low cost to make them, as compared to solid dies; however, they are not as robust as solid dies, so they are usually only used for short production runs.
File:Steel-rule die 2.png, A steel-rule die
File:Steel-rule die.png, A steel-rule die
File:Steel-rule die in press.png, Steel-rule die in a press
Rotary die
In the broadest sense, a ''rotary die'' is a cylindrical shaped die that may be used in any manufacturing field. However, it most commonly refers to cylindrical shaped dies used to process soft materials, such as paper or cardboard. Two rules are used, cutting and creasing rules. This is for corrugated boards whose thickness is more than 2 mm. Rotary dies are faster than flat dies.
The term also refers to dies used in the
roll forming
Roll forming, also spelled roll-forming or rollforming, is a type of rolling involving the continuous bending of a long strip of sheet metal (typically coiled steel) into a desired cross-section. The strip passes through sets of rolls mounted on ...
process.
Wire pulling
Wire
Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm
A wire is a flexible strand of metal.
Wire is c ...
-making dies have a hole through the middle of them. A wire or rod of
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
,
copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
, other metals, or
alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
enters into one side and is lubricated and reduced in size. The leading tip of the wire is usually pointed in the process. The tip of the wire is then guided into the die and rolled onto a block on the opposite side. The block provides the power to pull the wire through the die.
The die is divided into several different sections. First is an entrance angle that guides the wire into the die. Next is the approach angle, which brings the wire to the nib, which facilitates the reduction. Next is the bearing and the back relief. Lubrication is added at the entrance angle. The lube can be in powdered soap form. If the lubricant is soap, the friction of the drawing of wire heats the soap to liquid form and coats the wire. The wire should never actually come in contact with the die. A thin coat of lubricant should prevent the metal to metal contact.
For pulling a substantial rod down to a fine wire a series of several dies is used to obtain progressive reduction of diameter in stages.
Standard
wire gauge
Wire gauge is a measurement of wire diameter. This determines the amount of electric current the wire can safely carry, as well as its electrical resistance and weight.
Types of wire gauge
Wire gauges may be broadly divided into two groups, t ...
s used to refer to the number of dies through which the wire had been pulled. Thus, a higher-numbered wire gauge meant a thinner wire. Typical
telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
wires were 22-gauge, while main power cables might be 3- or 4-gauge.
References
Bibliography
*
Further reading
*J. R. Paquin and R. E. Crowley (1987). ''Die Design Fundamentals''. New York,
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
: Industrial Press Inc.
*David T. Reid (1991). ''Fundamentals of Tool Design''. Dearborn,
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...
: Society of Manufacturing Engineers.
*Jerry Arnold (1980). ''Die Makers Handbook''. New York,
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
: Industrial Press Inc.
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Cutting tools
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