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QUICK FACT GUIDES FOR MACHINISTS
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GUIDES
FUNDAMENTALS OF
DRILLING & TAPPING
FUNDAMENTALS
OF THREADING ON A LATHE
FUNDAMENTALS OF
WORKING BETWEEN CENTERS
FUNDAMENTALS
OF MILLING
FUNDAMENTALS
OF SAWING
METALWORKING
SHOP TERMS
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PRESSWORKING TERMS: ACCUMULATOR,
HYDRAULIC: A device employed
in hydraulic machinery for storing energy. AIR CUSHION:
An air-actuated die cushion. AIR DRAW:
A drawing operation performed in a single-action press with the blankholder
pressure supplied by an air cushion. AIR-HARDENING
STEEL: An alloy steel, also
called self-hardening steel, that will harden by cooling in still air from a
temperature higher than the transformation range. ALLOWANCE,
METAL: The area of excess
metal needed to complete any subsequent processing. BACK-GAGE:
A surface on two or more supports to locate behind the shear that can be
positioned accurately either manually or automatically to control size. BEAD:
A narrow ridge in a sheet-metal workpiece or part, commonly formed for
reinforcement. BED,
ADJUSTABLE: A press bed
which can be raised or lowered. BED, PRESS: The
stationary and usually horizontal part of a press that serves as a table to
which a bolster plate or lower die assembly is mounted. BEND
ALLOWANCE: The developed arc
length along the neutral axis of bent metal. BENDING: The
straining of material, usually flat sheet or strip metal, by moving it around a
straight axis which lies in the neutral plane. Metal flow takes place within the
plastic range of the metal, so that the bent part retains a permanent set after
removal of the applied stress. The cross section of the bend inward from the
neutral plane is in compression; the rest of the bend is in tension. BENDING DIE:
Dies of this class are designed for bending sheet metal or wire parts into
various shapes which are usually irregular and are produced either by pushing
the stock into cavities or depressions of corresponding shape in the die or by
the action of auxiliary attachments such as slides, etc., which are operated as
the punch descends. BEND RADIUS: (1)
The inside radius at the bend in the work: (2) The corresponding radius on the
punch or on the die. BEVEL
(ANGLE): Ninety degrees
minus the bend angle of a flange. For bend angles of less than 90 degrees the
bevel (angle) is termed an "open bevel"; for bend angles over 90
degrees, the bevel (angle) is termed a "closed bevel". BLANK:
A precut metal shape, ready for subsequent press operations. BLANK
DEVELOPMENT: (1) The
technique of determining the size and shape of a blank; (2) the resultant flat
pattern. BLANKHOLDER:
The part of a drawing or forming die which holds the workpiece against the draw
ring to control metal flow. BLANKING:
The operation of cutting or shearing a piece out of stock to a predetermined
contour. BLANKING DIE:
Dies of the "blanking class" are used for cutting blanks usually from
flat sheets or strips of stock; such blanks may or may not be drawn, formed or
bent, either by other parts combined with the blanking members, or by means of
separate dies. If the chief or only function of the die is to cut blanks, it is
a blanking die; if the blanking operation is followed by a more important
operation in the same die such as drawing, then the term drawing die would be
applied, the blanking part being considered a secondary feature of the design. BOLSTER
PLATE: Dies are usually held
in position on the bed of a punch press by means of a bolster or die
bed, although large dies are often attached directly to the press bed.
The principal function of a bolster are; (1) That of supplying an adequate
support for the die, and a means of holding the die in its proper position
relative to the punch. (2) Too furnish a means of attachment to the press. BUCKLING:
A bulge, bend, kink, or other wavy condition of the workpiece caused by
compressive stresses. BULGING:
The process of expanding the walls of a cup, shell, or tube with an internally
expanding segmental punch or punch composed of air, liquids, or semi liquids,
such as waxes or tallow, or of rubber and other elastomers. BURNISHING:
The process of smoothing or plastically smearing a metal surface to improve its
finish. BURRING:
A common term for "deburring" or smoothing the rough cut edges of
metal. BURR SIDE: The
side of a punched blank that presents a rough edge around its periphery or
around a hole or opening in it. In blanking operation, it is the face or side of
the blank that comes in direct contact with the punch. In piercing or
perforating operations, it is the face or side of the blank that comes in direct
contact with the die. BUSHING,
GUIDE POST: A replaceable
insert usually fitted in the upper shoe to provide better alignment. CAM ACTION:
A motion at an angle to the direction of an applied force, achieved by a wedge
or cam. CAMBER:
A slight convexity or bulging of sheet, strip, or plate as might appear when
looking along the edge. CAPACITY,
PRESS: The amount of force,
in tons, expected by a press slide near the bottom of its stroke. CHUTE:
A trough in which blanks, workpieces, or parts are fed to or conveyed from a die
or press. CLEARANCE,
DIE: The space, per side,
between the punch and die. CLOSING IN:
The process of forming a closed end on a tubular part. CLUTCH:
A device which connects and disconnects a driven machine member and a driving
machine member. COIL CRADLE:
A stand that supports and allows rotation of coil stock COINAGE
METALS: Alloys of gold or
silver with nickel or copper, used for minting coins. COINING:
A closed-die squeezing operation in which all surfaces of the work are confined
or restrained. COLD HEADING:
The process of upsetting the ends of bar, wire, or tube stock while cold. COLD WORKING:
Working of metal, such as by bending or drawing, to plastically deform it and
produce strain hardening. CRIMPING: A
forming operation used to set down, or close in, a seam. CUP:
Any shallow cylindrical part or shell closed at one end. CUPPING:
An operation that produces a cup-shaped part. CURLING:
Forming an edge of circular cross section along a sheet or at the end of a shell
or tube. See also Wiring. CUSHION,
HYDRAULIC: A die cushion
actuated by hydraulic pressure. See also Die Cushion. CUT-AND-CARRY
METHOD: A method in which
the part under fabrication is not entirely detached from the strip, or is pushed
back into the strip, for transport to a succeeding station in a progressive die.
DAYLIGHT:
See Shut Height. DEBURRING: Removing
burrs on a part. DEEP DRAWING:
The drawing of deeply recessed parts from sheet material through plastic flow of
the material, when the depth of the recess equals or exceeds the minimum part
width. DEFLECTION: The
deviation of a body from a straight line or plane when a force is applied to it.
DIAL FEED:
(1) A press feed which conveys the work to the dies by a circular motion; (2) a
mechanism which moves dies under punches by a circular motion and into definite
indexed positions. DIE:
(1) A complete tool consisting of a pair or a combination of pairs of mating
members for producing work in presses, including all supporting and actuating
parts of the tool; (2) the female part of a complete die. DIE,
ASSEMBLING: A die which
assembles and fastens parts together by riveting, press fitting, folding,
staking, curling, hemming, crimping, seaming, or wiring. DIE, BENDING: A die which permanently deforms sheet or strip metal along a straight axis. DIE,
BLANKING: A die for cutting
blanks by shearing. DIE, BRAKE:
A die used in a press brake. DIE, BURNISHING: A die which improves surface or size by plastically smearing the metal surface of the part. DIE, CAM: A
die in which the direction of moving elements is at an angle to the direction of
forces supplied by a press. DIE,
COMBINATION: A die in which
a cutting operation and a non-cutting operation on a part are accomplished in
one stroke of the press. The most common type of combination die blanks and
draws a part. DIE,
COMPOUND: A die in which two
cutting operations are accomplished in one press stroke. The most common type of
compound die, banks and pierces a part. DIE, COMPOUND
COMBINATION: A die in which
a part is blanked, drawn, and pierced in one stroke of the press. DIE, CURLING:
A forming die in which the edge of the work is bent into a loop or circle along
a straight or curved axis. DIE,
CUT-AND-CARRY: See Die,
Progressive. DIE,
DIMPLING: A forming die
which produces a conical flange (stretch flange) encircling a hole in one or
more sheets of metal. DIE,
DIMPLING, RAM-COIN: A
forming die which forms a conical dimple in two sheets, and rivets the sheets
together with some coining of a small ring like area are immediately surrounding
the hole. DIE, DINKING:
A die which consists of a press or hand-operated hollow punch with knife-edges
for cutting blanks from soft sheet metals and nonmetallic materials. DIE,
DOUBLE-ACTION: A die in
which pressure is first applied to a blank through the blank-holder and is then
applied to the punch. DIE,
EMBOSSING: A die set which
is relatively heavy and rigid for producing shallow or raised indentations with
little or no change in metal
thickness. DIE,
EXPANDING: A die in which a
part is stretched, bulged, or expanded by water, oil, rubber, tallow, or an
expanding metal punch. DIE,
EXTRUSION: A die in which a
punch forces metal to plastically flow through a die orifice so that the metal
assumes the contour and cross-sectional area of the orifice. DIE, FLOATING
(OR PUNCH): A die (or punch)
so designed that its mounting provides for a slight amount of motion, usually
laterally. DIE, FOLLOW:
See Die, Progressive. DIE, FORMING:
A die in which the shape of the punch and die is directly reproduced in the
metal with little or no metal flow. DIE, GANG: A
series of dies mounted on a die plate. DIE, HEADING:
(1) A die used in a forging
machine or press for upsetting the heads of bolts, rivets, and similar parts;
(2) a die used in a horizontal heading machine for upsetting the flanged heads
on cartridges and similar shells. DIE, HEMMING:
A die which folds the edge
of the part back over on itself; the edge may or may not be completely flattened
to form a closed hem. DIE, HORN: A
die in which a horn, mandrel, or anvil holds the work, usually on a horizontal
axis. DIE,
INVERTED: A die in which the
conventional positions of the male and female members are reversed. DIE, JOGGLE: A
die which forms an offset in a flanged section. DIE, LANCING:
A die which cuts along a
line in the workpiece without producing a separation in the workpiece and
without yielding a slug. DIE,
MULTIPLE: A die used for
producing two or more identical parts at one press stroke. DIE,
PERFORATING: A die in which
a number of holes are pierced or punched simultaneously or progressively in a
single stroke of the press. DIE,
PIERCING: A die which cuts
out a slug (which is usually scrap) in sheet or plate material. DIE,
PROGRESSIVE: A die in which
two or more sequential operations are performed at two or more stations upon the
work, which is moved from station to station. DIE,
PUNCHING: A term
interchangeable with Piercing Die. DIE,
RIVETING: A die that
assembles two or more parts together by riveting. DIE,
SECTIONAL (SEGMENTAL): A
die, punch, or form block which is made up of pieces, sections, laminations,
segments, or sectors. DIE, SHAVING:
A die usually having square cutting edges, negligible punch and die clearance,
and no shear on either punch or die. DIE, SHIMMY (BREHM
TRIMMING DIE): A cam driven
die which cuts laterally through the walls of shells in directions determined by
the position of cams. DIE, SIDE
ACTION: A type of die that
operates approximately at right angles to the motion of the press slide by means
of cams, wedges, or auxiliary press mechanisms. DIE,
SINGLE-ACTION: A drawing die
that has no blankholder action, since it is used with a single-action press
without the use of a draw cushion. DIE, SWAGING:
A die in which part of the metal under compression plastically flows into
contours of the die; the remaining metal is unconfined and flows generally at an
angle to the direction of applied pressure. DIE, TANDEM:
See Die, Two-Step. DIE.
TRIPLE-ACTION: A die in
which a third force is applied to a lower punch in addition to forces applied to
the blankholder and the punch fastened to the inner side. DIE,
TWO-STEP: A drawing or
reducing die in which the reduction is made in two stages or levels, one above
the other, in a single stroke of the press. DIE, WAFFLE:
A type of flattening die that sets a waffle or crisscross design in the blank or
workpiece without deforming it. DIE,
WEDGE-ACTION: A die has a
side motion actuated by a wedge surface. DIE BLOCK:
(1) A block or plate out of which the die proper is cut; (2) the block or plate
to which sections or parts of the die proper are secured. DIE CUSHION:
A press accessory located beneath or within a bolster or die block, to provide
an additional motion or pressure for stamping operations; actuated by air. oil,
rubber, or springs, or a combination thereof. DIE HEIGHT
(SHUT HEIGHT): The distance
from the finished top face of the upper shoe to the finished bottom face of the
lower shoe, immediately after the die operation with the work in the die. DIE HOLDER: A
plate or block upon which the die is mounted. DIEING
MACHINE: A high-speed
vertical press, the side of which is actuated by pull rods extending to the
drive mechanism below the bed. DIP PAD:
A movable plate or pad in a female die, usually for part ejection by mechanical
means, springs, or fluid cushions. DIE RADIUS:
The radius at the edge of a female die over which metal is formed or drawn into
the die. DIE SET:
A standardized unit consisting of a lower shoe, an upper shoe, and guide pins or
posts. DIE SHOE:
A plate or block upon which a die holder and in which guide posts are mounted. DIE SLIDE:
An attachment for sliding the lower part of a die set in and out of the press in
synchronization with the press stroke. DIE SPACE:
The maximum space within a press bounded by the top of the bed (bolster), the
bottom of the slide, and any other press parts. DIE SPRINGS: Heavy
wire springs used to exert force on a stripper plate, pressure plate, or cam
slides. These springs are purchased items. Careful calculations are normally
required to determine the number and size of the die springs required, and to
minimize travel for maximum life. DIE STAMPING:
The general term for a sheet-metal part that is formed, shaped, or cut by a die
in one or more press operations. DIMPLING:
Localized indent forming of sheet metal, so as to permit the head of a rivet or
bolt to fasten down flush with the service. DIRECTIONALITY
IN SHEET METAL: A property
resulting from the rolling process in its fabrication at the mill so that its
greatest tensile strength is in the direction of the rolling. DISHING:
Forming a large-radiused concave surface in a part DISTORTION:
Any deviation from a desired contour or shape. DOUBLE
SEAMING: The process of
joining metal edges, each edge being flanged, curled, and crimped. DRAFT: The
taper given to a die so as to allow the part to fall through the die or be
removed. DRAWABILILTY:
(1) A measure of the feasibility of deformation of a blank during a drawing
process; (2) percentage of reduction in diameter of a blank when its is drawn to
a shell of maximum practical depth. DRAWING: A
process in which a punch causes flat metal to flow into a die cavity to assume
the shape of a seamless hollow vessel. DRAWING DIES:
Drawing dies are used for drawing parts from flat stock into cylindrical and
various other shapes. There are several different classes of drawing dies,
including plain drawing dies, combination dies, double-action dies, and
triple-action dies. DRAWPIECE:
Any drawn part. DRAW RADIUS:
The radius at the edge of a die or punch over which the work is drawn. DRAW RING:
A ring-shaped die part (either the die ring itself or a separate ring), over the
inner edge of which the metal is drawn by the punch. DUCTILITY: The
property of a material that permits it to sustain permanent deformation in
tension without rupture. DWELL:
The time interval in a press cycle during which there is no movement of a press
member. EARING:
The formation of ears or scalloped edges around the top edge of a drawn shell
due to directional differences in the plastic-working properties of rolled sheet
metal. ECCENTRIC: A
machine element that converts rotary motion to straight line motion. EJECTION:
The removal of a part from a die by an air blast or mechanical means. ELASTICITY:
The property of a material which renders it capable of some return to its former
size and shape after any deformation. ELASTIC LIMIT:
The maximum stress to which a material can be subjected, and yet return to its
original shape and dimensions on removal of the stress. EMBOSSING:
A process that produces relatively shallow indentations or raised designs with
theoretically no change in metal thickness. ENERGY: The
capacity of a body for doing work, measured in terms of force and distance. EXTRUSION: The
plastic flow of a metal through a die orifice. EYELET
MACHINE: A multiple-slide
press, usually employing a cut-and-carry or a transfer feed for sequential
operations in successive stations. FALSE WIRING:
Curling the edge of a sheet,
shell, or tube without inserting a wire or rod inside the curl. FEED, DRUM: A feed in which the station dies are located on the periphery of a drum horizontally mounted in the die space. FEED, GRIP:
A type of feed mechanism employing a set of jaws to grip the stock and feed it
to the die. FEED HOPPER:
A bin designed to hold parts and with a mechanism which selects and
automatically feeds individual parts into a chute. FEED
INDEXING: A feed that
rotates blanks and parts for various operations, usually visually indicating the
position of the blank or part. FEED
MAGAZINE: The combination of
a magazine and a mechanism for holding of parts and feeding one unit of the work
at a time. FEED, ROLL: A
die feed operated from the press slide or crankshaft, in which the stock is
moved by gripping rollers. FLARING:
(1) The process of forming an outward flange on a tubular part; (2) forming a
flange on a head. FLASH (FIN):
The excess metal attached to a part after a forming operation. FLATTENING:
The truing of metal surfaces by the use of resrtrike dies, or other methods. FLUTING: The
forming of longitudinal recesses in a cylindrical part. FLYING CUTOFF
DEVICE: A cutting die, saw,
or wheel that cuts work to length while it is moving. FORM BLOCK: A
punch or die used in the rubber-pad process to form materials. FORM,
MECHANICAL: A special die
used in rubber-pad forming to perform operations which cannot be made with
simpler, regular form blocks. FORMING: Making
any change in the shape of a metal piece which does not intentionally reduce the
metal thickness. FORMING DIES:
Forming dies are a type of die in which a blank is formed into a hollow shape by
simply being pushed into a cavity of the required shape in the die, or a
previously drawn cup is given a different shape by compressing it between a
punch and die which conforms to the desired shape. FORM RADIUS: See
Radius, Die. FOULING: The
adherence of particles of a part to a punch or die. FOUR SLIDE
PRESS: A press (also called
a multislide machine) equipped with a progressive die for automatically
producing small, intricately shaped parts. GAG:
A metal spacer to be inserted so to render a floating tool or punch inoperative.
GAGE:
A device used to position a working die accurately. GAGE FINGER: A
manually operated device to limit the liner travel of material. GALLING:
The friction-induced roughness of two metal surfaces in direct sliding contact GENEVA MOTION
(STAR WHEEL MOTION): An
intermittent motion, sometimes used in dial and drum feeds, in which a part of
the driving shaft's motion is transmitted to a driven shaft. GUIDE POSTS
(GUIDE PINS; LEADER PINS):
Pins or posts usually fixed in the lower shoe and accurately fitted to bushings
in the upper shoe to ensure precise alignment of two members of a die set. BEAD BLOCK:
A block or plate usually mounted on or attached to a lower die, and serving to
prevent or minimize deflection of punches or cams. HITCH FEED: See
Feed Grip. HOLE
FLANGING: Tuning up or
drawing out a flange around a hole; also called "extruding". HYDROPRESS:
A single-action hydraulic press, equipped with a rubber pad. INCHING: A
control process in which the motion of the working members is precisely
controlled in short increments. INDENTING
(POCKETING): The forming of
depressions of appreciable size and with fairly square walls, e.g., the
indenting of the primer hole in a shell case. INDEXING:
Rotating a part angularity and sequentially performing a press operation. INSIDE-OUT-REDRAWING:
See Reverse Drawing. INTERLOCK: A
device mutually interacting with another device to govern succeeding operations
in the same or allied device. IRONING: An
operation in which the thickness of the shell wall is reduced and its surface
smoothed. JOG
(JOGGING): See Inching.
JOGGLE: An
offset surface consisting of two adjacent, continuous or nearly continuous
short-radius bends of opposite curvature. KIRKSITE:
Trade name of a zinc-base alloy used principally in low-production dies. KNEE: See
Bed, Adjustable. KNIFE-EDGE
CUTTERS: See Die, Dinking
or Steel Rule Die. KNOCKOUT:
A mechanism for ejecting blanks or other work from a die. Commonly located on
the slide, but may be located under the bolster. See Liftout. LANCING:
Cutting along a line in the workpiece without producing a detached slug from the
workpiece. LEADER PINS:
See Guide Posts. LIFTERS:
See Vacuum-cup Lifters. LIFTOUT
(BOTTOM KNOCKOUT): A
mechanism located on the bolster or press bed for ejecting a part from the die,
or raising it to a level for advancing to another station as in progressive
dies. LIGHTENING
HOLE: A hole punched in a
part for the purpose of saving weight. LIMIT SWITCH:
A type of electric switch
used to control the operations of a machine automatically. LOAD (PRESS):
Amount of force exerted in a
given operation. LOADING:
See Pickup. LUBRICANT:
Any substance which has the specific property of reducing friction between two
surfaces in contact. LUDERS' LINE:
Depressed elongated markings parallel to the direction of maximum shear stress,
or elevated elongated markings appearing on the surface of some materials,
particularly on iron and low-carbon steel, when deformation is beyond the yield
point in tension or compressing, respectively. MAGAZINE:
A chute like bin in which parts are uniformly positioned for feeding. MEHANITE:
The trade name for nodular cast irons having high compressive strengths;
commonly cast into large dies, punch, and other die elements. MILD STEEL:
Usually SAE 1010 to 1020 steel. MILL FINISH:
A surface finish produced on sheet and plate, characteristic of the ground
finish on the rolls used in fabrication. MOTION
DIAGRAM: A graph showing the
relative motions of the moving members of a machine. NECKING
(NECKING IN): Reducing the
diameter of a portion of the length of a cylindrical shell. NEST: (1)
To stack parts within one another to occupy minimum space, (2) a plate having an
opening to conform to the contour of a part, used to locate the part in a die;
(3) to lay out a blank so that the outlines of parts produced will interlock
with each following and each preceding part and require the minimum amount of
material. NORMALIZING:
A process in which a ferrous alloy is heated to a suitable temperature above the
critical range and then cooled in air at room temperature. NOSING: Forming
a curved portion, with reduced diameters, at the end of a tubular part. NOTCH
BRITTLENESS: The inherent
brittleness in areas containing a groove, scratch, sharp fillet, or notch. NOTCHING:
The cutting out of various shapes from the edge of a strip, blank, or part. OIL CANNING
(CANNING): The distortion of
a flat or nearly flat surface by finger pressure, and its reversion to normal. OLSEN
DUCTILITY TEST: A test for
indicating the ductility of sheet metals by forcing a hemispherical shaped punch
or hardened ball into the metal and measuring the depth at which fracture
occurs. OVERBENDING:
Bending metal a greater amount than that called for in the finish piece, so as
to compensate for spring-back. OVERLOAD
RELIEF BED: A press bed with
a built in cushion, usually of the hydropneumatic type, which depress at a
predetermined overload. PAD:
The general term used for that part of a die which delivers holding pressure to
the metal being worked. PARTING:
An operation usually performed to produce two or more parts from one common
stamping. PERFORATING:
The piercing or punching of many holes, usually identical and arranged in a
regular pattern. PICKOFF:
An automatic device for removing the finished part from a die, after it has been
stripped, or released from the die. PICKUP:
The adherence of particles of metal to a die surface in contact with the metal
being worked. PIERCING:
The process of die-cutting holes in a sheet or plate material. PILOT: A
pin or projection provided for locating work in subsequent operations from a
previously punched or drilled holes. PLANCHETTE:
A metal disk with edges milled ready for coining. PLANISHING: A
hammering operation in which parts are given a dense smooth surface finish by a
rapid succession of blows delivered by highly polished dies or by a planishng
hammer. PLASTIC FLOW:
The phenomenon which takes place when a substance is deformed permanently
without rupture. PLASTICITY: The
property of a substance that permits it to undergo a permanent change in shape
without rupture. PLASTIC
WORKING: The processing of a
substance by causing a permanent change in its shape without rupture. PLATENS: The
sliding member or ram of a power press. PNEUMATIC DIE
CUSHION: See Die Cushion.
PNEUMATIC
TOGGLE LINKS: Main links of
a toggle press which are equipped with pneumatic cushions to give air pressure
controlled flexibility. PREFILL
VALVE: A pressure-actuated
valve required for controlling the prefilling (or exhausting) of oil during fast
traverse operation of hydraulic press ram cylinders. PERFORMED
PART: A partially formed
part which will be subjected to one or more subsequent operation. PREHEATING:
A general term used to describe heating applied as a preliminary to some further
thermal or mechanical treatment. PRESS:
A machine having a stationary bed or anvil, and a slide (ram or hammer) which
has a controlled reciprocating motion toward and away from the bed surface and
at right angles to it, the slide being guided in the frame of the machine to
give a definite path of motion. PRESS, ARBOR:
A press originally developed for forcing arbors or mandrels into holes and
similar assembling. PRESS, ARCH
TYPE: A type of press having
its columns arched outward to permit a wider bed and slide flange, left to
right, between columns. PRESS,
AUTOMATIC: A press whose
action is synchronized with mechanically fed work. PRESS, CAM: A
press in which one or more of the slides are cam-actuated. PRESS,
C-FRAME: A press having
uprights or housings resembling the form of the letter C. PRESS, CRANK:
A crankshaft actuated
mechanical press. PRESS,
DOUBLE-ACTION MECHANICAL: A
press having one slide within the other, the outer slide usually being toggled
or cam-operated, resulting in independent parallel slide movements. PRESS,
DOUBLE-CRANK: A mechanical
single-action pres in which two cranks on the same shaft operate the slide. PRESS,
ECCENTRIC: A mechanical
press in which an eccentric is used to move the slide instead of a crankshaft. PRESS,
ENCLOSED: A press having
most of its working parts enclosed. PRESS, END
WHEEL: A mechanical press
with flywheel at the back, and a shaft running front to back. PRESS,
FLYWHEEL: A mechanical press
which has the flywheel mounted directly on the crankshaft. PRESS, FOOT:
A type of press powered entirely by foot pressure. PRESS,
FOUR-POINT SUSPENSION: A
press whose slide is actuated by four connections. PRESS,
FRONT-TO-BACK SHAFT: A press
having its main shaft running front to back. PRESS, GAP
(OVERHANG): See Press
C-Frame. PRESS GEARED:
A press whose main crank or eccentric shaft is connected to the drive shaft or
flywheel shaft by one or more sets of gears. PRESS,
HORIZONTAL: A press in which
the ram or slide movement is horizontal. PRESS, HORN
(HORNING): A press equipped
with or arranged for a horn. PRESS,
HYDRAULIC: A press actuated
by a hydraulic cylinder and piston PRESS,
INCLINABLE: A press whose
main frame may be tilted backward, usually up to 45 degrees, to facilitate
ejection of parts by gravity through an open back. PRESS,
INCLINED: A press built so
that it is permanently inclined to a fixed non vertical position. PRESS,
KNUCKLE-JOINT: A heavy
powerful short stroke press in which the
slide is actuated by a toggle (knuckle) joint. PRESS,
MECHANICAL: A press having a
slide (or slides) actuated by mechanical means. PRESS,
MULTIPLE-SLIDE: (1) A press
having individual slides built into the main slide, or (2) a press of more than
one slide in which each slide , has its own connection to the main shaft. PRESS,
NOTCHING: A mechanical press
used for notching internal and external circumferences and also for notching
along a straight line. These presses are equipped with automatic feeds, since
only one notch is made per stroke. PRESS, OBI:
See Press, Open-Back Inclinable. PRESS,
ONE-PIECE FRAME: A press
whose bed, uprights, and crown are composed of a single casting or weldment. PRESS,
ONE-POINT: A mechanical
press in which the slide is operated by one
connection to the shaft. It is usually a single crank type or a single eccentric
press of the enclosed type. PRESS,
OPEN-BACK: A gap press
designed to facilitate feeding from front to back and ejection from the back.
PRESS,
OPEN-BACK INCLINABLE: An
inclinable press in which the opening at the back and between the uprights is
usually slightly more than the left-to-right dimension of the slide flange. See
also Press, Inclinable. PRESS,
OPEN-ROD: A hydraulic press
with vertical rods instead of uprights to guide the slide. PRESS,
OSCILLATING-DIE: A press in
which a reciprocating and or rotary motion of the die and punch is synchronized
with the feed. PRESS,
OVERHANG: A gap press in
which the frame overhangs the bed. PRESS,
PILLAR: A small press, with
straight sides, commonly used for subpress work. PRESS, PUNCH:
(1) Most commonly, and
end-wheel gap press of the fixed-bed type; (2) a name loosely used to designate
any mechanical press. PRESS, RACK
AND PINION REDUCING: A long
stroke reducing press actuated by a rack and pinion. PRESS,
REDUCING: A long stroke,
single crank press used to redrawing (reducing) operations. PRESS,
RUBBER-PAD: Any single
action hydraulic press with its slide equipped with a rubber pad for rubber pad
forming. PRESS,
SIDE-WHEEL: Any press with a
flywheel at the side and a left-to-right crankshaft. PRESS,
SINGLE-ACTION: Any press
with a single slide; usually considered to be without any other motion pressure
device. PRESS,
SINGLE-PIECE: See Press,
One-Piece Frame. PRESS , SOLID
FRAME: See Press,
One-Piece Frame. PRESS,
STRAIGHT SIDE: An upright
press open at front and back with the columns (uprights) at the ends of the bed. PRESS,
TAPERING: A press designed
to permit placing a blank in a die without the need for a slide plate, and to
deliver an exceptionally long stroke. PRESS,
TIE-ROD: A type of press in
which four steel tie rods hold the bed, uprights, and crown together under a
predetermined compressive load. PRESS,
TOGGLE: (1) Any mechanical
press in which a slide, or slides, are actuated by one or more toggle joints;
(2) a term applied to double, triple, action presses. PRESS, TOGGLE
DRAWING: A press in which
the outer or blankholder slide is actuated by a series of toggle joints and the
inner slide by the crankshaft or eccentrics. PRESS,
TRIMMING: A special purpose
mechanical press in which shearing and trimming operations are usually done on
forgings. PRESS,
TRIPLE-ACTION: A press
having three slides with three motions synchronized for such operations as
drawing, redrawing, and forming, where the third action is opposite in direction
of the first two. PRESS, TRYOUT
(SPOTTING): A press used in
final finishing of dies to locate inaccuracies of mating parts. PRESS,
TWIN-DRIVE: A press having
two main gears on the crankshaft meshing with two main pinions of the first
intermediate shaft. PRESS,
TWO-POINT: A mechanical
press in which the slide is operated by two connections to the crankshaft. PRESS,
UNDERDRIVE: A press in which
the driving mechanism is located within or under the bed or below the floor
line. PRESS, WATCH
(WATCHMAKER'S BENCH PRESS: A
small end-wheel gap press having a comparatively high die space to allow the use
of a subpress. PRESS,
WIRING: Any press of several
types used for wiring operations. PRESS-BRAKE
(BENDING BRAKE): An
open-frame press for bending, cutting, and forming; usually handling relatively
long work in strips. PRESS
TONNAGE: See Capacity,
Press. PRESSURE
ATTACHMENT: See Die
Cushion. PRESSURE
SWITCH: An electrical switch
operated at a predetermined pressure. PUCKERING:
A wavy condition in the walls of deep drawn parts. PULL FEED:
See Feed, Grip. PUNCH: (1)
The male die part, usually the upper member and mounted on the slide;
(2) to die-cut a hole in sheet or plate material (see Piercing);
(3) a general term for the press operation of producing holes of various sizes
in sheets, plates, or rolled shapes. PUNCH HOLDER:
The plate or part of the die which holds the punch. QUICK-RETURN
MOTION DRAG-LINK MOTION: A
motion used on crank presses to provide fast upward slide travel. QUILL-TYPE
PUNCH: A frail or
small-sized punch mounted in a shouldered sleeve or quill. RABBIT EAR:
A recess in a die corner to allow for wrinkling or folding of the blank. RACK-AND-PINON
DRIVE: A drive incorporating
a rack and pinion and commonly used to actuate roll reeds. RAM:
See Plunger, Platen, Slide. SCRAP:
Pieces or parts not normally usable. SCRAP CUTTER:
A shear or cutter operated by the press or built into a die for cutting scrap
into sizes for convenient removal from the die. SEAM: (1)
The fold or ridge formed at the junction of two pieces of sheet metal; (2) on
the surface of a metal, a crack that has been closed but not welded; usually
produced by some defect either in casting or in working, such as blow holes that
have become oxidized, or folds and laps that have formed during working. SEAMING:
The process of joining two edges of sheet metal by multiple bending. SEIZING: Welding
of metal from the workpiece to a die member under the combined action of
pressure and sliding friction. SETBACK:
The distance from the intersection of two corresponding mold lines to the bend
line. SHANK,
PUNCH-HOLDER: The stem or
projection from the upper shoe which enters the slide flange recesses and is
clamped to the slide. SHAVING:
A secondary shearing or cutting operation in which the surface of a previously
cut edge is finished or smoothed. SHEAR: (1)
A tool for cutting metal and other material by the closing motion of two sharp,
closely adjoining edges; (2) to cut by shearing dies or blades; (3) an
inclination between two cutting edges. SHEDDER: A
pin, or, ring, or plate, operated by mechanical means, air, or rubber cushion,
that either ejects blanks, parts, or adhering scrap from a die, or releases them
from a punch, die, or pad surface. SHEET:
Metal having a thickness up to 1/4inch. SHEET-METAL
GAGE: Refers to standard
identification on of sheet-metal thickness. SHOE:
(1) A metal block used in bending processes to form or support the part being
processed; (2) the upper or lower component of a die set. SHUT HEIGHT
OF A PRESS: The distance
from the top of the bed to the bottom of the slide with the stroke down and
adjustment up. In general, the shut height of a press is the maximum die height
that can be accommodated for normal operation, taking the bolster into
consideration. SIZING: A
secondary pressworking operation to obtain dimensional accuracy by metal flow. SLIDE:
The main reciprocating press member; also called, the ram, plunger, or the
platen. SLITTING:
Cutting or shearing along single lines; used either to cut strips from a sheet,
or to cut along lines of a given length or contour in a sheet or part. SLUG: A
small piece of material, usually scrap, produced in piercing or punching holes
in sheet material. SPACER BLOCK:
See Riser Block. SPALLING: The
breaking off of flake like metal particles from a metal surface. SPOTTING:
The fitting of one part of a die to
another, by applying an oil color to the surface or the finished part and
bringing it against the surface of the intended mating part, the high spots
being marked by the transferred color. SPRING-BACK:
The extent to which metal tends to return to its original shape or position
after undergoing a forming operation. SPRING
CUSHION: See Die Cushion.
STAKING:
The process of permanently fastening two parts together by recessing one part
within the other and then causing plastic flow of the material at the joint. STAMP:
(1) The general term to denote all pressworking; (2) to impress lettering or
designs by pressure into the surface material. STEEL RULE
DIE: A metal-cutting die
employing a thin strip of steel (printers rule) formed to the outline of a part
and a thin steel punch mounted to a suitable die set. A flat metal plate or
block of wood is substituted for the punch when cutting nonmetallic materials
and soft metals. STOP,
AUTOMATIC: (1) A device for
positioning stock in a die; (2) a mechanism that initiates the stopping action
of a press after its complete cycle; (3) a device for initiating the stopping
action of a press at the start of operating troubles, such as misfeeding,
buckling of strip stock, or nondischarge of blanks, for the protection of the
die or the operator. STOP PIN:
A device for positioning stock or parts in a die. STRAIGHTENER
ROLLS: See Roll
Straightner. STRAIN: The
deformation, or change in size or shape of a body, produced by stress in that
body. Unit strain is the amount of deformation (usually in inches ) per unit
length (usually in inches). STRAIN
HARDENING: The increase in
hardness and strength in a metal caused by plastic deformation at temperatures
lower than the recrystallization range. STRESS:
The internal force or forces set up within a body by outside applied forces or
loads. Unit stress is the amount of load per unit area. STRESS
CRACKING: The cracking of
parts which have retained residual stresses from cold forming, heat treating, or
rapid cooling. STRETCH
(STRETCHER) FORMING: the
shaping or forming of a sheet by stretching it over a formed shape. STRETCHER
STAINS: See Luder's
Lines. STRIKING: A
general term for making a quick and forceful (hitting) contact between a punch
and the work. STRIPPER:
A device for removing the workpiece or part from the punch. STRIPPER
PLATE: A plate (solid or
movable) used to strip the workpiece or part from the punch; it may also guide
the stock. STRIPPING:
The operation of removing the workpiece or part from the punch. STROKE OF
PRESS: The reciprocating
motion of a press slide, specified as the number of inches between the terminal
point of the motion. SUBPRESS:
A small cylindrical die set in which the upper and lower members are
incorporated in a self-contained unit so arranged to always hold the die members
in alignment. SWAGING: A
squeezing operation in which part of the metal under compression plastically
flows into contours of the die; the remaining metals unconfined and flows
generally at an angle to the direction of the applied pressure. TABLE:
Sometimes called a "knee". See Bed, Adjustable. TABLE FEED:
A device and expression for feeding rubber-pad presses, consisting of tables
upon which the dies, form blocks, and blanks are mounted, which are then rolled
into place under the rubber a
platen. TAPERING:
A swaging or reducing operation, in which the metal is elongated in compression,
for producing conical surfaces on tubular parts. TEMPERING
(DRAWING): A heat-treatment
process for removing internal stresses in metal at temperatures above those for
stress relieving, but in any case above the lower critical temperature. TENSILE
STRENGTH: The ultimate
strength of a material, measured in pounds per square inch in tension on the
original cross section tested, which, if exceeded, causes sectional deformation
leading to ultimate rupture. TENSION:
The internal force or forces set up within a body, and causing or tending to
cause extension or stretching. THREE-POINT
BENDING: A bending operation
which the blank is placed on two supports and a force is applied between the
supports. THROAT (GAP: The
open space in a gap-frame press behind the slide center line. THROW: In
crank and eccentric pressed, a distance equal to one-half the stroke. TIN PLATE:
Sheet steel coated with tin from 0.0003 to 0.002 inches thick, applied by the
hot-dipping process. TOGGLE JOINT:
A connecting mechanism consisting of two links freely pinned together at one end
and connected by free pins to the other machine parts at their other or outer
ends. TONNAGE,
PRESS: See Capacity,
Press. TOP STOP:
An automatic device for stopping a press at the top of a stroke, i.e., after
each cycle. TORQUE:
Any twisting effort which produces or tends to produce rotation. TORSION: The
internal resistance of a body to a torque acting upon that body. TRIMMER,
FLAT-EDGE: A machine in
which a cam driven lower die moves horizontally to cut or notch drawn shells. TRIMMING:
Trimming is the term applied to the operation of cutting scrap off a partially
or fully shaped part to an established trim line. TRIMMING,
PUNCH: Trimming the edge of
a tubular part by pinching or pushing the flanges or lips of the part over the
cutting edge of a draw or stationary punch. TRIPLE
ACTION: Any operation on
sheet metal in which three separate motions are required. TRIPPING
MECHANISM: Any auxiliary
mechanism, either manually, mechanically, or automatically operated, which
stops, starts, or otherwise controls the operation the primary mechanism. ULTIMATE
STRENGTH: The maximum stress
which a material can withstand before rupture. UNIFORM
STROKE MOTION: A type of
motion obtainable with a drag-link mechanism, in which a fairly uniform speed of
slide is obtained during a large portion of the working stroke. UPSETTING:
A squeezing or compressing operation in which a larger cross sections formed on
the part by gathering material in such a way as to reduce the length. VACUUM-CUT
LIFTER: A mechanism for
lifting or moving blanks or strips from a stack by means of rubber suction cups
attached to lifting or feeding arms. VENT: A
small hole in a punch or die for admitting air to avoid suction holding, or to
relieve pockets of trapped air which would prevent proper die closure or action.
WIPER BLOCK: A
metal block used to exert pressure during the wiper forming of sections. WIPER FORMING
(WIPING): A method of
curving work over a form block or die in which the form block is rotated
relative to a wiper or slide block. WIRING:
The curling or forming of a curled edge of a sheet or tube which a wire or rod
inserted within the curled edge. WORK:
Any material part or piece that is being processed or handled to or
from a processing operation. WRAP FORMING:
See Stretcher Forming.
WRINKLING:
A wavy condition on metal parts, due to buckling under compressive stresses. YIELD POINT:
The stress at which a pronounced increase in strain is shown without an increase
in stress. |
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