CPC Definition - Subclass B21C

Last Updated Version: 2020.05
MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
Definition statement

This place covers:

The methods and devices for working metal as follows:

Metal drawing (covered by B21C 1/00 - B21C 19/00)

Metal extrusion (covered by B21C 23/00 - B21C 35/00)

Methods for manufacturing metal sheets, bars, wires tubes or the like. (covered by B21C 37/00)

Devices for cleaning metal products adapted for use with machines of this subclass (covered by B21C 43/00)

Separating mandrels from work (covered by B21C 45/00)

Winding-up, coiling, winding-off metal wire or metal band (covered by B21C 47/00)

Devices for temporarily accumulating material (covered by B21C 49/00)

Measuring, gauging, indicating, counting, marking devices adapted for use with subclasses B21B - B21F (covered by B21C 51/00)

Other subject-matter concerning the manufacture of metal sheets, wire, rods, tubes or profiles otherwise than by rolling as well as other subject-matter concerning auxiliary operations used in connection with metal-working without essentially removing material (covered by B21C 99/00).

References
Limiting references

This place does not cover:

Working or processing of sheet metal or metal tubes, rods or profiles

B21D

Informative references

Attention is drawn to the following places, which may be of interest for search:

Methods for manufacturing metal sheets, bars, wires tubes or the like by rolling

B21B

Devices for cleaning metal sheet from scale, i.e. descaling, in combination with rolling

B21B 45/00

Making forged or pressed products

B21K

Soldering, welding

B23K

Other working of metal, combined operations

B23P

Transport or storage devices, e.g. conveyors for loading

B65G

Handling thin or filamentary material, e.g. sheets, webs, cables

B65H

Devices for cleaning in general

C08B

Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
Definition statement

This place covers:

Methods, devices and drives for metal drawing.

Metal drawing consists in reducing the cross-section of a work piece (e.g. reducing the diameter of a metal rod or wire) by forcing it through a die. Metal drawing differs from extrusion by the lower rate of reduction.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Profiling tools for metal drawing tools, dies and mandrels

B21C 3/00

Pointing

B21C 5/00

Cooling, heating or lubricating drawing material

B21C 9/00

{Drawing materials of special alloys so far as the composition of the alloy requires or permits special drawing methods or sequences}
Definition statement

This place covers:

All aspects relating to drawing special alloys with the purpose, for example, of modifying the physical properties of such alloys, and all special drawing methods.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Modifying the physical properties by deformation during manufacturing of ferrous alloys rods or wires

C21D 8/065

Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working

C22F 1/00

Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core, the wires being characterised by an anticorrosive or adhesion promoting coating

D07B 1/0666

{using vibratory energy}
Definition statement

This place covers:

All aspects relating to drawing metal sheets, metal wire, metal rods, metal tubes applying vibratory energy, for example, to the mandrel and/or the dies.

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Drawing metal wire or like flexible metallic material by drawing machines or apparatus in which the drawing action is effected by drums
Definition statement

This place covers:

All aspects relating to the drawing action effected by drums.

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with two or more dies operating in series
Definition statement

This place covers:

All aspects relating to drawing dies operating in series.

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in which the material slips on the drums
Definition statement

This place covers:

All aspects relating to wire drawing devices and methods whereby positive slip insures that all portions of the wire are taut and that there is adequate frictional force exerted on the wire by the drums to pull the wire through the dies.

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in which the material does not slip on the drums
Definition statement

This place covers:

All aspects relating to wire drawing devices and methods whereby wire slips on the drawing drums are eliminated.

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with accumulation of material between consecutively-arranged dies
Definition statement

This place covers:

All aspects relating to wire drawing devices and methods whereby a certain amount of wire is accumulated in order, for example, to allow steady operation of the machine, even though the speeds of the various drums are not in exact proportion to the elongation of the wire.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Devices for temporarily storing filamentary material during forwarding, e.g. for buffer storage

B65H 51/20

Regulating or controlling speed of drawing drums, e.g. to influence tension; Drives; Stop or relief mechanisms (couplings for drums B21C 1/14; design or construction of electrical equipment, see the relevant classes)
Definition statement

This place covers:

All aspects relating to wire drawing devices and methods, whereby drums are controlled to apply the correct tension on the wire.

Details of drives for drums.

Stop or relief mechanisms.

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References
Limiting references

This place does not cover:

Drums, e.g. capstans; Connection of grippers; Grippers specially adapted for drawing machines or apparatus of the drum type; Couplings specially adapted for these drums

B21C 1/14

Drums, e.g. capstans (capstans or winches in general B66D); Connection of grippers thereto; Grippers specially adapted for drawing machines or apparatus of the drum type; Couplings specially adapted for these drums
Definition statement

This place covers:

All aspects relating to wire drawing capstans and gripping means cooperating with said capstans.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Capstans or winches in general

B66D

Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes
Definition statement

This place covers:

All aspects relating to metal drawing devices and methods not provided in the sub-groups.

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from stock of limited length (B21C 1/22 takes precedence)
Definition statement

This place covers:

All aspects relating to drawing devices and methods from solid stocks of limited length.

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References
Limiting references

This place does not cover:

Metal drawing by machines specially adapted for making tubular articles

B21C 1/22

from stock of essentially unlimited length (B21C 1/22 takes precedence)
Definition statement

This place covers:

All aspects relating to drawing devices and methods from stock of unlimited length.

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References
Limiting references

This place does not cover:

Metal drawing by machines specially adapted for making tubular articles

B21C 1/22

specially adapted for making tubular articles (bending sheet metal into tubular form by drawing B21D 5/10)
Definition statement

This place covers:

All aspects relating to drawing devices and methods specially adapted for making tubular articles, also starting from stock of limited length.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Tube-rolling not restricted to methods provided for in only one of groups B21B 17/00, B21B 19/00, B21B 21/00, e.g. combined processes

B21B 23/00

Bending sheet metal along straight lines, e.g. to form simple curves for making tubes

B21D 5/10

Rigid pipes wound from sheets or strips, with or without reinforcement, made of metal

F16L 9/165

by means of mandrels (mandrels B21C 3/16)
Definition statement

This place covers:

All aspects relating to drawing devices and methods specially adapted for making tubular articles by means of mandrels.

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References
Limiting references

This place does not cover:

Mandrels; Mounting or adjusting same

B21C 3/16

Informative references

Attention is drawn to the following places, which may be of interest for search:

Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies; {Making tubes with angled walls, ribbed tubes and tubes with decorated walls}

B21C 37/20

Push-bench drawing
Definition statement

This place covers:

All aspects relating to drawing devices and methods specially adapted for making tubular articles by means of mandrels by push-bench drawing.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Mandrels; Mounting or adjusting same

B21C 3/16

Tube-rolling not restricted to methods provided for in only one of groups B21B 17/00, B21B 19/00, B21B 21/00, e.g. combined processes

B21B 23/00

Shaping without cutting, by deep-drawing

B21D 22/20

Carriages; Drives
Definition statement

This place covers:

All aspects relating to drawing carriages and drives.

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Carriages; Connections of grippers thereto; Grippers (for drawing machines of the drum type B21C 1/14)
Definition statement

This place covers:

All aspects relating to drawing carriages, connections of grippers thereto and grippers.

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References
Limiting references

This place does not cover:

Grippers for drawing machines of the drum type

B21C 1/14

Drives, e.g. carriage-traversing mechanisms; Driving elements, e.g. drawing chains; Controlling the drive {(endlessly revolving chain systems for metal coiling: B21C 47/3458)}
Definition statement

This place covers:

All aspects relating to drives for drawing.

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References
Limiting references

This place does not cover:

Endlessly revolving chain systems

B21C 47/3458

Informative references

Attention is drawn to the following places, which may be of interest for search:

Removing or drawing-off work

B21C 35/02

Forwarding filamentary material; Aprons, endless belts, lattices, or like driven elements

B65H 51/14

{Linear motor pulling devices}
Definition statement

This place covers:

All aspects relating to electric linear motors for drawing.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path; Linear motors; Sectional motors

H02K 41/02

Feeding or discharging the material or mandrels
Definition statement

This place covers:

All aspects relating to feeding or discharging the material or mandrels.

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Guiding or supporting the material or mandrels
Definition statement

This place covers:

All aspects relating to guiding or supporting the material or mandrels.

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Profiling tools for metal drawing; Combinations of dies and mandrels
Definition statement

This place covers:

All aspects relating to metal drawing tools (dies, die holders, mandrels).

media1.jpgSource: WO2008010614

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Metal drawing machines, methods or drives

B21C 1/00

Pointing

B21C 5/00

Cooling, heating or lubricating drawing material

B21C 9/00

Pointing; Push-pointing
Definition statement

This place covers:

Reducing the cross-section of the material's leading end for easing its insertion into the drawing die prior to drawing.

media2.jpgSource: DE3634229

Cooling, heating or lubricating drawing material (B21C 3/14 takes precedence)
Definition statement

This place covers:

All aspects of cooling, heating or lubricating the drawing material and/or the drawing devices or dies.

media3.jpgSource: DE19817088

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Metal drawing machines, methods or drives

B21C 1/00

Metal drawing tools, dies and mandrels

B21C 3/00

Lubricants in general

C10M

Devices for straightening wire or like work combined with or specially adapted for use in connection with drawing or winding machines or apparatus
Definition statement

This place covers:

Devices either:

  • for straightening wire, wherein the straightening action is realized by using drawing dies, or
  • for straightening wire, which devices are used in combination with wire drawing or winding machines (e.g. straightening prior to drawing).
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Winding, coiling

B21C 47/00

Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made there from.

B21D 3/08

Working of wire by straightening

B21F 1/02

Extruding metal; Impact extrusion
Definition statement

This place covers:

Methods and devices for metal extrusion; products obtained by metal extrusion as well as lubrication aspects.

The title refers to impact extrusion. This is however only one specific metal extrusion technique covered by this group.

Metal extrusion consists in forcing solid metal through a suitably shaped orifice using compressive forces. Metal extrusion differs from metal drawing by the higher rate of reduction.

media4.jpgSource: US2007227221

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Continuous casting

B22D

Extrusion of plastic material

B29C 48/00

{to improve the material properties, e.g. lateral extrusion}
Definition statement

This place covers:

All aspects relating to extrude metals with the purpose of improving the physical properties of such metals, for example, through severe plastic deformation such as ECAP and ECAE.

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References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting from material of particular form or shape, e.g. mechanically pre-treated

B21C 23/01

Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough

B21J 1/025

Modifying the physical properties of iron or steel by deformation by cold working

C21D 7/02

Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working

C22F 1/00

Profiling tools for metal extruding
Definition statement

This place covers:

Dies and mandrels for metal extrusion, including dies and mandrels for coating work by extrusion or having a section variable during extruding.

The extrusion die and/or mandrel define/s the section through which the billet is forced, thereby defining the cross sectional shape of the extruded product.

media5.jpgSource: WO2007029888

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Rams or plungers; Discs therefor
Definition statement

This place covers:

Rams or plungers for metal extrusion; the disks therefore as well as the dummy blocks.

The extrusion ram or plunger is normally the element applying the extrusion pressure to the billet to be extruded.

media6.jpgSource: DE10036463

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Containers for metal to be extruded (B21C 29/02 takes precedence)
Definition statement

This place covers:

The container is the element into which the billet is placed and pressurized for extrusion.

media7.jpgSource: DE3342617

References
Limiting references

This place does not cover:

Containers comprising cooling or heating elements

B21C 29/02.

Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Cooling or heating work or parts of the extrusion press; {Gas treatment of work}
Definition statement

This place covers:

All aspects relating to heating or cooling in combination with metal extrusion.

media8.jpgSource: GB1058854

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Control devices, e.g. for regulating the pressing speed or temperature of metal (B21C 25/08 takes precedence); Measuring devices, e.g. for temperature of metal, combined with or specially adapted for use in connection with extrusion presses (measuring devices of more general interest within subclass B21C, see group B21C 51/00)
Definition statement

This place covers:

Control devices, e.g. for regulating the pressing speed or temperature of metal; Measuring devices, e.g. for temperature of metal, combined with or specially adapted for use in connection with extrusion presses.

media9.jpgSource: EP2361700

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Measuring devices of more general interest

B21C 51/00

Feeding extrusion presses with metal to be extruded {; Loading the dummy block}
Definition statement

This place covers:

All aspects concerning operations or devices upstream of the extrusion press or extrusion process, and specifically linked to it, including e.g.feeding conveyors and grippers used to provide a workpiece to an extrusion press.

media10.jpgSource: EP0486436

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Removing work or waste from extrusion presses; Cleaning

B21C 35/00

Removing work or waste from extruding presses; Drawing-off extruded work (in connection with the extruding of bent tubes or rods B21C 23/12); Cleaning dies, ducts, containers, or mandrels
Definition statement

This place covers:

All aspects concerning operations or devices downstream of the extrusion press or extrusion process, and specifically linked to it, including e.g.:

  • Removing work or waste from extruding presses;
  • Drawing off extruded work;
  • Cleaning dies, ducts, containers or mandrels.
  • Scrapers and scraping knives for cutting-off or removing the waste or for removing sections from the extruded work, e.g. removing a strip to create an open profile.

media11.jpgSource: EP0787543

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Extrusion devices and methods

B21C 23/00

Tools for metal extrusion (i.e. mandrels and dies)

B21C 25/00

Rams, plungers or disks therefore

B21C 26/00

Containers for metal to be extruded

B21C 27/00

Cooling or heating work or parts of the extrusion press

B21C 29/00

Control or measuring devices in relation with extrusion

B21C 31/00

Feeding extrusion presses with metal to be extruded

B21C 33/00

Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for (by rolling B21B; by working or processing semi-finished sheet metal, profiles, tubes, or wire B21D or B21F; by casting B22; by material-removing machine tools B23; by welding, e.g. cladding or plating B23K; by grinding or polishing B24; by electroforming C25D 1/00; by drawing or extruding, see the relevant groups); Manufacture of tubes of special shape
Definition statement

This place covers:

Processes and devices for the manufacture of:

Metal sheets (covered by B21C 37/02).

Metal wires (covered by B21C 37/04).

Metal tubes (covered by B21C 37/08-B21C 37/14).

Metal tubes of special shape (covered by B21C 37/15-B21C 37/298).

Finishing tubes, e.g. sizing, burnishing (covered by B21C 37/30).

media12.jpgSource: EP1880776

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Metal extrusion devices and methods

B21C 23/00

Bending of metal sheet along straight lines

B21D 5/00

Manufacture of metallic fibers

B23P 17/06

Devices for cleaning metal products combined with or specially adapted for use with machines or apparatus provided for in this subclass
Definition statement

This place covers:

All aspects relating to cleaning metal products, wherein the cleaning action is realized by using machines of B21C or wherein the cleaning action is used in combination with machines of B21C.

This group includes in particular, cleaning metal products, especially descaling, by metal drawing, or with methods associated to metal drawing or winding processes.

media13.jpgSource: WO2006200502

Separating mandrels from work or vice versa
Definition statement

This place covers:

Separation of mandrels from work or vice-versa.

media14.jpgSource: JP61092708

Winding-up, coiling or winding-off metal wire, metal band or other flexible metal material characterised by features relevant to metal processing only (coiling wire into particular forms B21F 3/00; hot coilers in connection with heat-treatment apparatus C21D 9/68)
Definition statement

This place covers:

Methods and devices for coiling (winding) and uncoiling (unwinding) of metal wire, band or similar metal product.

Associated operations, like feeding or guiding the material, transferring coils, joining wire or band ends, treating the material, holding on drums or coil holders.

media15.jpgSource: US5170653

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Joining metal sheets

B21B 15/0085

Coiling wire into particular form

B21F 3/00

Unwinding welding material

B23K 9/1333

Furnace coilers, Hot coilers

C21D 9/68

Winding electrical elements

H01F 41/00, H02K 15/00

Devices for temporarily accumulating material
Definition statement

This place covers:

Devices for temporarily accumulating metallic material (e.g. metal bands or wires).

media16.jpgSource: DE4243409

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Accumulating rolled material

B21B 41/00

Accumulating material in general

B65H 20/00

Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F
Definition statement

This place covers:

Mainly detecting flaws of metal sheets and positioning or marking said flaws.

However, this group has been conceived very generally, which is reflected in its content.

media17.jpgSource: WO2011145168

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Embossing, marking

B44B

Measuring

G01N

Subject matter not provided for in other groups of this subclass
Definition statement

This place covers:

Subject-matter not provided for in other groups of this subclass concerning the manufacture of metal sheets, wire, rods, tubes or profiles otherwise than by rolling

Subject-matter not provided for in other groups of this subclass concerning auxiliary operations used in connection with metal-working without essentially removing material.