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 |  موضوع: كتاب Jig and Fixture Design الخميس 17 مارس 2022, 12:02 am | |
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Jig and Fixture Design, Fifth Edition
Edward G. Hoffman
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Contents
Preface Xi
Section I Basic Types and Functions of Jigs and Fixtures 1
Unit 1 Purpose of Tool Design 1
Objectives 1
Tool Design 1
Tool Design Objectives 1
Tool Design in Manufacturing 1
Planning the Design 2
Challenges to the Tool Designer 3
Requirements to Become a Tool Designer 6
Summary 6
Review 6
UNIT 2 TYPES AND FUNCTIONS OF JIGS AND FIXTURES 8
Objectives 8
Jigs and Fixtures 8
Classes of Jigs 8
Types of Jigs 9
Types of Fixtures 13
Classification of Fixtures 17
Summary 19
Review 19
UNIT 3 SUPPORTING AND LOCATING PRINCIPLES 21
Objectives 21
Referencing
Basic Rules for Locating 21
Planes of Movement 25
Locating the Work 26
Summary 38
Review 38
UNIT 4 CLAMPING AND WORKHOLDING PRINCIPLES 41
Objectives 41
Workholders 41
Basic Rules of Clamping 41
Types of Clamps 43
Non-Mechanical Clamping 53
Special Clamping Operations 60
Clamping Accessories 61
Summary 62
Review 63
UNIT 5 BASIC CONSTRUCTION PRINCIPLES 65
Objectives 65
Tool Bodies 65
Preformed Materials 66
Drill Bushings 67
Set Blocks 72
Fastening Devices 73
Summary 86
Review 86
SECTION II CONSIDERATIONS OF DESIGN ECONOMICS 89
UNIT 6 DESIGN ECONOMICS 89
Objectives 89
Considerations of Design Economics 89
Design Economics 89
Design Economy 89
Economic Analysis 90
Comparative Analysis 95
Summary 97
Formula Summary 98
Review 99
UNIT 7 DEVELOPING THE INITIAL DESIGN 100
Objectives 100
Predesign Analysis 100
Designing Around the Human Element 102
Previous Machining Operations
Developing Tooling Alternatives 107
Note Taking 107
Summary 107
Review 108
UNIT 8 TOOL DRAWINGS 109
Objectives 109
Tool Drawings versus Production Drawings 109
Simplified Drawings 110
Making the Initial Drawing 115
Dimensioning Tool Drawings 116
Millimeter and Inch Dimensioning 118
Geometric Dimensioning and Tolerancing 122
Supplementary Symbols 126
Geometrically Dimensioned and Toleranced Tool Drawings 132
Computers in Tool Design 132
Summary 134
Review 136
SECTION III DESIGNING AND CONSTRUCTING JIGS AND FIXTURES 139
UNIT 9 TEMPLATE JIGS 139
Objectives 139
Template Jigs 139
Variations of Template Jigs 139
Design Procedures 141
Tool Design Application 146
Summary 146
Review 149
UNIT 10 VISE-HELD AND PLATE FIXTURES 150
Objectives 150
Vise-Held Fixtures 150
Designing a Vise-Held Fixture 151
Plate Fixtures 155
Designing a Plate Fixture 156
Calculating Cam Clamps 158
Tool Design Application 165
Cam Design Application 168
Summary 168
Review 168
UNIT 11 PLATE JIGS 170
Objectives 170
Plate Jigs 170
Designing a Plate Jig
Designing a Table Jig 177
Designing a Sandwich Jig or a Leaf Jig 181
Tool Design Application 184
Summary 185
Review 188
UNIT 12 ANGLE-PLATE JIGS AND FIXTURES 189
Objectives 189
Variations and Applications 189
Designing an Angle-Plate Jig 191
Designing an Angle-Plate Fixture 194
Tool Design Application 200
Summary 200
Review 203
UNIT 13 CHANNEL AND BOX JIGS 204
Objectives 204
Channel Jigs 204
Designing a Channel Jig 205
Box Jigs 208
Designing a Box Jig 208
Tool Design Application 212
Summary 213
Review 213
UNIT 14 VISE-JAW JIGS AND FIXTURES 216
Objectives 216
The Machine Vise 216
Locating Work in Vise-jaw Workholders 217
Designing a Vise-jaw Jig 219
Designing a Vise-jaw Fixture 222
Tool Design Application 224
Summary 226
Review 227
SECTION IV SPECIALIZED WORKHOLDING TOPICS 231
UNIT 15 POWER WORKHOLDING 231
Objectives 231
Types of Power-Workholding Systems 231
Basic Operation of Power-Workholding Systems 235
Benefits of Power Workholding 236
Summary 237
Review
UNIT 16 MODULAR WORKHOLDING 239
Objectives 239
Modular Fixturing Systems 240
Modular Fixturing Applications 250
Summary 255
Review 256
UNIT 17 WELDING AND INSPECTION TOOLING 257
Objectives 257
Tooling for Welding Operations 257
Modular Fixturing for Welding 260
Inspection Fixtures 263
Summary 266
Review 268
UNIT 18 LOW-COST JIGS AND FIXTURES 269
Objectives 269
Chucks and Chucking Accessories 269
Collets and Collet Accessories 275
Vises and Vise Accessories 284
Specialty Clamps and Workholding Devices 294
Summary 302
Review 303
UNIT 19 TOOLING FOR NUMERICALLY CONTROLLED MACHINES 304
Objectives 304
Introduction 304
Basic N/C Operation 304
The Cartesian Coordinate System 305
Incremental and Absolute Programming 307
Types of N/C Systems 308
Tooling Requirements for Numerical Control 309
Types of Workholders 309
Summary 314
Review 315
UNIT 20 SETUP REDUCTION FOR WORKHOLDING 316
Objectives 316
Benefits of Setup Reduction 316
The Setup Reduction Process 317
Summary 325
Review 326
UNIT 21 TOOL MATERIALS 309
Objectives 327
Properties of Tool Materials
Ferrous Tool Materials 330
Nonferrous Tool Materials 334
Nonmetallic Tool Materials 336
Designing with Relation to Heat Treatment 340
Summary 342
Review 342
APPENDIX 345
GLOSSARY 347
PROFESSIONAL ORGANIZATIONS 357
INDEX
Accumulator. A device installed between the
clamps and the power source in a power-workholding system. It is charged with either fluid or
gas and maintains the necessary pressure in the
system when the power is disconnected.
Adjustable Locator. A locator used on jigs and fixtures and made to be adjusted after installation on
the tool body.
Adjustable Support. A support, or locator, positioned under the part and made to be adjusted to
suit individual parts.
Air-Assisted Hydraulic System. A form of powerworkholding system where compressed air is
used to activate the hydraulic pressure through a
booster. This is the most common form of powerworkholding system.
Allowance. The intentional difference between the
sizes of mating parts in an assembly.
Alloy. A mixture of metals that have been combined
to form the alloy in order to gain desired characteristics.
Alloy Steel. A steel made up of several substances in
addition to carbon and iron.
American Sequence. A sequence of information in
a feature control symbol. The sequence is geometric characteristic symbol, datum reference,
and tolerance value.
Angle-Plate Fixture. A modified form of plate fixture
used to machine a part at an angle to its locator.
Angle-Plate Jig. A modified form of plate jig used
to machine a part at an angle to its locator.
Angularity. The geometric characteristic that specifies a specific angular relationship between two
surfaces of a part.
Assembly Drawing. A mechanical drawing that
shows all the parts and elements of a tool in their
assembled form.
Basic Dimension. A theoretically perfect dimension
used to locate part features or datums. This type
of dimension is shown enclosed in a box on the
part drawing.
Basic Size. The size of a part to which the tolerance
values are applied to obtain the limits of size.
Bilateral Tolerance. The tolerance value that may
go in both a plus and a minus direction from the
basic size.
Bismuth Alloys. A group of metals having a bismuth base which is used primarily for cast tooling parts. These alloys are commonly referred to
as low-melt alloys.
Booster. A device that provides the power to operate a power-workholding system. Boosters are
classified as either air operated or electrically
operated.
GlossaryBoring Jig. A type of jig specifically designed for
boring operations. This jig normally has some
type of tool guide, or bushing, on both sides of
the hole being machined rather than on just one
side, as is the case with a drill jig.
Box Jig. A form of jig that completely encloses the
part being machined. This jig is also called a
tumble jig.
Bracket Method. A dual dimensioning method in
which the converted dimensions are shown in
brackets ([ ]).
Break-Even Point. The minimum number of parts
required for a tool to pay for itself. Any number
of parts less than this break-even point will result
in a loss, while any number over this point will
result in a profit.
Brinell Hardness. A specific measure and rating of
a material’s resistance to penetration or indentation. A Brinell hardness test is performed by forcing a steel ball 10 millimeters in diameter into the
material with a force, or load, of 3000 kilograms.
Brittleness. The characteristic of a metal that causes
it to fail when sudden loads are applied. This is
normally considered to be a negative quality, but
in some cases, as with shear pins, it may be a positive characteristic of the material.
Built-Up Tool Body. A form of tool body used for
jigs and fixtures in which the entire construction
consists of a series of parts screwed and doweled
together. This is the most common and least
expensive tool body.
Burr. The rough ribbon, or ridge, of metal formed
on both sides of a machined hole. The larger
ridge, normally on the exit side of the hole, is
referred to as the primary burr, while the smaller
ridge, on the side of the hole where the drill
enters, is called the secondary burr.
CAD. The acronym for computer aided design.
CAM. The acronym for computer aided manufacturing.
Cam. A mechanical device used to clamp parts in a
jig or fixture. The two fundamental types are flat
and conical.
Cap Screw. A type of mechanical fastener used to
assemble the parts of a jig or fixture. Typically
these fasteners have a cylindrical head with an
internal hexagon drive.
Carbon Steel. A specific type of steel composed
mainly of iron and carbon. The three standard
types or designations of carbon steel are low,
medium, and high carbon.
Cast Iron. A cast ferrous material with a higher carbon content than carbon steel; it is used for both
manufactured parts and tooling. Composed mainly of iron, carbon, and other elements.
Cast Tool Bodies. Tool bodies made from cast iron,
cast aluminum, or other castable materials.
Channel Jig. A specific style of jig that has a Ushaped channel as its major structural element.
Chuck. A commercially available workholder, used
mainly on a lathe or grinder, which holds parts
with a series of jaws.
Circular Runout. The geometric characteristic that
specifies a relationship between two or more concentric diameters of a part measured in single line
elements around the part.
Circularity. The geometric characteristic that specifies a condition of roundness in a part feature.
Clamp. A mechanical device used to hold a part
securely in a jig or fixture.
Clamping Forces. The forces exerted by the clamping
device while holding the part in the workholder.
Closed Jig. A jig that encompasses a part on more
than two sides.
CNC. Computer numerical control. The abbreviation is used to describe a system where a computer controls the movements of a machine tool
through a direct interface, floppy disk, or a magnetic tape used as an input medium.
Collet. A mechanical device used to hold parts, normally of a specific diameter or size, that are to be
turned or rotated around a central axis.
Component Libraries. The groups of individual
types of components, such as clamps, locators,
etc., used for fixturing applications with CAD.
Concentricity. The geometric characteristic that
specifies a concentric relationship between two
or more diameters of a part.
Conical Wedge. A wedge that has a tapered form,
similar to a solid mandrel.
348 GlossaryContinuous Path. A programming method used for
numerically controlled machine tools in which
the position of the tool is constantly controlled
throughout the complete machining cycle.
Conversion Chart Method. A dual dimensioning
method in which the converted dimensions are
shown in a chart along with the design units they
reference.
Critical Dimension. A part dimension that controls
the size or location of a part feature that is very
important to the overall function of the part.
Cutting Forces. The forces exerted against the part
by the cutter during the machining cycle.
Cylindrical Cam. A cam design that uses a cylindrically shaped element to activate the clamping
device. This cam may use the outside surface of
the cylinder or a groove cut into the surface of the
cylinder.
Datum. A point, line, surface, or feature considered to
be theoretically exact that is used to locate the part
or the geometric characteristic features of the part.
Datum Feature Symbol. The datum reference letter
contained in a rectangular box and used to note
the datum surfaces on the part.
Datum Reference. The letter values contained in the
feature control symbol which reference the control to the appropriate datum feature symbols.
Degrees of Freedom. The 12 degrees, or directions,
of movement an unrestricted part is free to make.
These directions include six radial and six axial
directions of movement.
Detailed Drawing. A mechanical drawing that
shows each part of a larger assembly drawn in a
series of individual views. This is the primary
type of drawing used to manufacture each part.
Diamond Pin. A specific type of relieved locating
pin used for jigs and fixtures. The pin, when
viewed from the end, has a diamond shape.
Dowel Pin. A hardened steel pin used to locate assembled parts of a workholder or as a locating device to
accurately position the parts in a jig or fixture.
Dowel-Pin System. A modular tooling system that
uses a series of precisely located holes and dowel
pins to accurately position and locate the various
elements used to build the modular tool.
Drill Bushing. A hardened steel or carbide bushing
used to guide and support a cutting tool, such as a
drill, throughout its machining cycle.
Drill Jig. A special purpose tool used to accurately
position, support, and hold a workpiece so that a
variety of operations may be performed. Drill
jigs also use some type of cutter guiding device,
such as a drill bushing, to accurately position and
support the cutting tool.
Dual Dimensioning. A dimensioning system used
to show both inch and millimeter dimensions on
the same print.
Duplex Tools. Jigs and fixtures designed and constructed so that two parts may be machined. As
one part is machined, the other station is loaded
or unloaded. When the first part is complete, the
second part is moved to the cutter and the first is
unloaded and a new part loaded. This process is
continued until all the parts are completed.
Eccentricity. The condition of a part in which two
diameters do not share the same center-line positions.
Ejector. A device, contained within a workholder, that
is used to aid in the removal of the part from the tool.
Epoxy Resins. A family of plastic tooling compounds
used to prepare cast nests or other types of workholding or locating devices. They normally consist
of two elements, a resin and a hardener, that are
mixed and cast to prepare the required element.
Equalizing Support. A supporting device used to
spread the support over a larger area of the part. It
normally has two contact points; as one is
depressed, the other rises.
Expanding Mandrel. A mechanical holding device
that grips the workpiece in an internal diameter
or other shaped hole and exerts outward pressure
to hold the part.
Feature Control Symbol. The symbol used in geometric dimensioning and tolerancing which contains the geometric characteristic symbol, tolerance
value, and datum reference.
Feeler Gauge. A flat metal strip of precise thickness that is used to reference the cutters to a
fixture by establishing their relationship to the
set block.
Glossary 349Ferrous Metals. Metals and alloys that have a base
primarily of iron.
F.I.M. The abbreviation for full indicator movement.
Fixed-Limit Gauge. A gauge that has fixed limits of
size. Many times these gauges are go–no-go and
check the upper and lower limits of the part size.
Fixed-Renewable Bushings. Easily replaceable
drill bushings designed to be used in a liner bushing and which are held in place with a lock screw
or clamp.
Fixed-Stop Locators. External locators that are not
adjustable. All types of nonadjustable external
locators are fixed-stop locators.
Fixture. A workholding device that holds, supports,
and locates the workpiece while providing a referencing surface or device for the cutting tool.
Fixture Key. A square or rectangular block attached
to the base of a jig or fixture which locates and
aligns the workholder in the “T”-slots of the
machine tool on which it is used.
Flat Cam. A cam design that uses the outside profile
of a flat plate to generate the desired movement.
The two principal types of flat cam are the spiral
and the eccentric.
Flatness. The geometric characteristic that specifies
an amount of permitted variation from a perfectly
flat surface.
Flush-Pin Gauge. A type of inspection fixture that
uses a pin to indicate the part’s compliance to
specific sizes.
Foolproofing. The process of installing a device on
a jig or fixture to prevent improper loading of
parts in the tool.
Form Characteristics. The geometric characteristics
that control the form of a part. These include
straightness, flatness, circularity, and cylindricity.
Gang Milling. A milling operation using more than
two milling cutters to obtain a specific part size,
shape, or form.
Gauge. A mechanical device of a known and precise
size, used to check or compare part sizes.
Gauging Fixture. A fixture that uses some type of
gauge to check the sizes of a part.
Geometric Characteristic Symbols. The symbols
used to show the specific type of feature control
required for the part.
Geometric Dimensioning and Tolerancing. An
exact dimensioning method used to show the
exact specifications of part size and form.
Go–No-Go Gauges. Gauging devices used to check
the upper and lower limits of a part size.
Groove Pin. A pin made with a series of grooves or
ridges around its profile. Its use is similar to that of
a dowel pin, but it is not as accurate because it is
positioned in a drilled rather than a reamed hole.
Hardness. The property of a material that permits it
to resist penetration or indentation.
Heat Treatment. The process of using heat to modify the properties of a metal.
Hook Clamp. A type of commercially available
clamp used for holding parts in jigs and fixtures.
Inch. The base unit used for linear measurements in
the U.S. Customary System of measurement.
Indexing. The process of accurately spacing holes
or other details around a central axis.
Inspection. The process of checking a workpiece to
verify its conformity to the specifications in the
part print.
Inspection Tooling. Fixtures and other tools used to
aid in the process of inspecting parts.
International Sequence. The sequence of information in a feature control symbol. The sequence is
geometric characteristic symbol, tolerance value,
and datum reference.
Jaws. The mechanical devices or elements of a
workholder, such as a vise or chuck, that actually
contact the part being held.
Jig. A workholding device that holds, supports, and
locates the workpiece while providing a guiding
device for the cutting tool.
Jig Pin. A pin used to hold approximate alignment
between two or more parts of a tool. It can act as a
hinge pin or locator pin and can also be used to
attach removable parts to a jig or fixture.
Jig Plate. The part of a jig that contains the drill
bushings.
Knurled Bushings. Drill bushings made with a
knurled outside diameter to provide a positive
gripping surface in soft materials or to hold the
bushings when they are cast into the jig plate.
Lead Time. The time between the design and the
construction of a jig or fixture.
350 GlossaryLeaf Jig. A specific jig design that uses a hinged leaf
as a jig plate.
Least Material Condition. The condition of a part
feature in which it has its least amount of material allowed by the tolerance. It is the largest size
of an internal feature and the smallest size of an
external feature. It is also referred to as the LMC.
Limit Dimensions. Dimensions shown on a part
drawing that specify the maximum and minimum
sizes of a part feature.
Limits of Size. The maximum and minimum sizes
of a part as specified by the tolerances and the
basic size.
Liner Bushing. A drill bushing specifically used to
provide a hardened, wear-resistant hole in a jig
plate in which either slip- or fixed-renewable drill
bushings are installed.
Location Characteristics. The geometric characteristics that control the location of part features. These
characteristics include position and concentricity.
Locator. A device used to establish and maintain the
position of a part in a jig or fixture to insure the
repeatability of the workholder.
Low-Melt Alloys. A group of metals having a bismuth base that are used primarily for cast tooling parts.
Machinability. The measure of a material’s ability
to be machined. Some materials are soft and have
good machinability characteristics, while others
are harder and have poor machinability.
Machine Vise. A vise designed and intended to be
used on a machine rather than on a bench. The
most common types of machine vise are the
milling machine vise and the drill press vise.
Magnetic Chuck. A mechanical workholder that
uses magnetic force to hold a ferrous workpiece.
These chucks may use either an electromagnetic
or a permanent-type magnet.
Mandrel. A solid bar used to mount and drive parts
from a central hole. This bar appears to be cylindrical, but is actually conical since it has a .006-
inch taper per foot.
Manifold. A unit used to split or redirect the
hydraulic fluid in a power-workholding system.
The manifold has one inlet and many outlets for
several power clamps.
Maximum Material Condition. The condition of a
part feature in which it has the maximum amount of
material permitted by the tolerance. It is the smallest size of a hole or the largest size of an external
part feature. This is also referred to as the MMC.
Metric System. The common term used to identify
the Systeme Internationale d’Unites, or the International System of Units.
Millimeter. The base unit of linear measurement in
the Systeme Internationale d’Unites for manufacturing purposes.
Modifiers. The letter values used to modify tolerance values or datum references in a feature control symbol. These include the circled letters M,
L, and S.
Modular Tooling. A system of individual parts
assembled for a variety of jigs and fixtures.
Another term frequently used to describe these
tools is erector set tooling.
Multistation Tooling. Workholders that are capable
of holding and positioning more than one part at
a time.
N/C. Numerical control. N/C systems typically use
either punched paper or mylar tape to convey the
instructions to the machine tool.
Nest Locator. A type of locating device that encloses all or part of the outer profile of a part.
Numerical Control. An automated manufacturing
system that uses numerical data, usually on a
punched tape or in a computer, to operate a variety of machine tools.
Nuts. Mechanical fastening devices used to secure
bolts in assembled units.
Oil-Groove Bushing. A special-purpose drill bushing that has grooves cut into the inner surface to
provide complete lubrication to the cutting tool
or boring bar used in the drill bushing.
Open Jig. A variation of a drill jig, used to machine
parts on less than two sides.
Orientation Characteristics. The geometric characteristics that control the orientation of part features. These include angularity, parallelism, and
perpendicularity.
Parallelism. The geometric characteristic that specifies a relationship between two parallel surfaces
of a part.
Glossary 351Part. The object, or workpiece, machined in a jig or
fixture.
Part Drawing. The drawing, or print, of the object
to be made or machined.
Perpendicularity. The geometric characteristic that
specifies a perpendicular relationship between
two surfaces of a part.
Pin. A cylindrical fastener that is normally pressed
into a premachined hole for the purpose of aligning or holding parts of an assembled workholder.
Planes of Movement. The three principal planes, or
axes, or a part used to reference the twelve degrees
of freedom. These are generally identified as X, Y,
and Z.
Plate Fixture. A fixture that has a plate as its main
structural component.
Plate Jig. A jig with a plate as its main structural
component.
Pneumatic Workholding System. A form of
power-workholding system that uses air pressure
to operate all workholding devices.
Point-to-Point. A programming method used for
numerically controlled machine tools, in which the
position of the tool is controlled between a series of
specific locations, or points. Only the position of
these points is important; the path the tool takes
between these points is not important.
Position. The geometric characteristic that specifies
a relationship between a part feature and a central
axis, or center
Position Method. A dual dimensioning method in
which the converted dimensions are shown either
below or to the right of the design units. The units
are separated with a slash (/) for horizontal
dimensions and a straight line (–) for vertically
placed dimensions.
Power Clamping. A clamping system, either
hydraulic, pneumatic, or a combination of both,
used to activate and hold the clamping pressure.
Precast Tool Bodies. Commercially available tool
bodies made from cast aluminum, cast iron, or
cast steel; they need only minimal machining to
accommodate the various clamps and locators
required for the part being held.
Precision Ground Materials. Commercially available tooling components used in the construction
of built-up tool bodies. The two principal types
are cylindrical, called drill rod, and flat.
Preformed Materials. Commercially available
materials made in a variety of precast forms
which are used to construct built-up tool bodies.
Press-Fit Bushings. Drill bushings specifically designed and intended to be pressed into a hole in
the jig plate. The friction and pressure of the press
fit are the forces that hold the bushing in place.
Primary Locators. The locators used to locate, or
reference, the primary locating surface of the part.
Process Planning. The act, or process, of planning
the step-by-step procedure to be used to manufacture or machine a workpiece.
Production Plan. The document specifying the
exact means and methods to be used to manufacture a part or product.
Production Run. The specific group, or number, of
parts to be made at one time.
Profile. The external edges, or surfaces, of a part.
Profile Characteristics. The geometric characteristics that control the form, or shape, of a part profile. These include the profile of a line and the
profile of a surface.
Profiling Fixture. A fixture specifically designed to
aid in machining the external edges of a part.
Projected Tolerance Zone. The imaginary zone
projected above a part feature, such as a hole, to
insure assembly with a mechanical fastener passing through both the tolerance feature and the
projected thickness of the mating part.
Projection. A means of establishing the relative
position of the views in a mechanical drawing.
The two main types of projection in use today are
first angle (Europe) and third angle (United
States and Canada).
Pump Jig. A commercially available tooling device
used as the major structural element in some
types of jigs. This device consists of a base and a
top plate connected and aligned with two or more
posts. The top plate is moved up and down with
an integral handle.
Quarter-Turn Screw. A commercially available
fastening device used for clamping on some
types of workholders. The head of this screw is
flat and is usually used to clamp tooling ele-
352 Glossaryments, such as leaves, where the screw is positioned in a slot and turned 90 degrees (one quarter turn) to grip the top plate.
Reference Dimension. A dimension shown on a
part print for information purposes and used for
reference rather than manufacture. Such a dimension is shown in parentheses or with the abbreviation “REF.”
Reference Surface. A part surface used to reference the
part. It may also be referred to as a datum surface.
Referencing. The proper positioning of the workpiece with reference to the tool.
Regardless of Feature Size. A modifier used to
indicate that the tolerance value shown applies
regardless of the size of the feature or datum.
Releasing Agent. A compound used in conjunction
with epoxy resins to prevent the resins from
adhering to the part used as a pattern.
Renewable Bushings. Easily replaceable drill bushings designed to be used in liner bushings and
held in place with a screw or clamp. The two
principal variations are the fixed-renewable and
the slip-renewable bushing.
Repeatability. The feature of a workholder that permits the parts being machined to be duplicated
within the stated limits of size, part after part.
Resins. The compounds, usually epoxy, mixed
together to make resin tools.
Retaining Rings. Spring steel rings that are used in
place of nuts or screws to hold the part on which
they are installed in some relative position.
Rise. The term used to describe the movement of a
cam per degree of arc.
Rockwell Hardness. A specific measure and rating of
a material’s resistance to penetration or indentation.
A Rockwell hardness test is performed by forcing
either a diamond cone or a steel ball into the surface
of a part under a known and controlled load.
Rotary Tooling. A term used to describe indexing
jigs and fixtures.
Runout Characteristics. The geometric characteristics that control the runout of a part. These
include circular runout and total runout.
Sandwich Jig. A type of drill jig that holds the workpiece on two opposite sides. It may be used to support the part or to machine the part from two sides.
Screw Clamp. A clamping device that uses a screw
thread to clamp the part.
Secondary Locator. A locator used to reference the
secondary locating surface of the part.
Serrated Bushing. A drill bushing made with a serrated outside diameter to provide a positive gripping
surface in soft materials or to hold the bushing when
it is cast into the jig plate.
Set Block. A gauging device included on many fixtures
to aid in setting the cutters to suit the workpiece.
Set Screw. A mechanical fastening device that is generally made without a head and used for adjustable
locators or as a locking device for other applications.
Setup Gauge. A special-purpose gauge used in conjunction with a set block to establish the proper cutter position. A feeler gauge is a form of setup gauge.
Shear Strength. The measure of a material’s resistance to forces acting in opposite directions,
causing a shearing effect on the part.
Shop-Air System. The compressed air system
found in machine shops. The shop-air system
provides power to a variety of shop equipment.
Air tools, coolant systems, and power-workholding systems rely on this power source. The
most common shop-air systems use compressed air at a pressure of 90 to 100 pounds
per square inch.
Sight Locators. Locators used on jigs and fixtures
that are intended to be used for approximate location. The part may be aligned against milled slots
or scribed lines.
Slip-Renewable Bushings. Easily replaceable drill
bushings designed to be used in a liner bushing
and held in place with a screw.
Slot Nuts. A term used to describe T-nuts.
Socket-Head Cap Screws. A type of mechanical
fastener used to assemble the parts of a jig or fixture. Typically these fasteners have a cylindrical
head with an internal hexagon drive.
Software. The medium used to convey specific
instructions to a computer.
Solid Locators. Locators used on jigs and fixtures
which are solid and nonadjustable.
Spiral Cams. A type of flat cam that has a shape
similar to an involute curve.
Glossary 353Split Pin. A pin made from flat material formed into
a cylindrical shape with a split on one side. Its
use is similar to that of a dowel pin but it isn’t as
accurate because it is used in a drilled rather than
a reamed hole. Also called roll pin.
Straddle Milling. A milling operation using two
milling cutters to mill two sides of a part at the
same time.
Straightness. The geometric characteristic that
specifies a relationship between a part feature
and a true straight plane or line.
Strap Clamp. A specific type of clamping device that
uses a metal bar, similar to a strap, to hold the part
securely to the workholder. The basic elements of
this clamp are the strap, the hold-down bolt, and
the heel pin or block.
Structural Sections. Commercially available materials made in a variety of preformed shapes which
are used to construct built-up tool bodies.
Subplate. A plate containing many drilled and
tapped holes to which a variety of different components and clamps may be attached to form a
crude type of modular tooling.
Support. A locator placed under a workpiece.
Swing Clamp. A variation of a screw clamp consisting of an arm that swings about a stud at one end
and contains the screw clamp at the other end.
Systeme Internationale d’Unites. The system of
measurement frequently called the metric system.
T-Bolt. A mechanical fastener that has a head designed
to fit into the “T”-slots of machine tools. Usually
used to mount workholders to a machine tool.
T-Nut. A nut made specifically for use in the “T”-
slots of machine tools. Using these nuts permits
standard bolts to be used to attach the workholder or other elements.
“T”-Slot System. A modular tooling system that
uses a series of precisely located “T”-slots to
accurately position and locate the various elements used to build the modular tool.
Table Jig. A variation of the basic plate jig that uses
legs to elevate the jig off the machine table.
Tacking. A preliminary welding process in which
the joined edges are tacked, or welded, with
small widely spaced weld deposits to hold the
relative position prior to finish welding.
Template. A plate that duplicates the desired part
configuration and is used as a guide for layout
work or for light machining.
Template Jig. A jig that has a template as its major
structural element.
Tensile Strength. The measure of a material’s resistance to being pulled apart. The tensile strength
rating is the principal means used to classify the
strengths of various metals.
Tertiary Locator. A locator used to reference the
tertiary locating surface of the part.
Thread Inserts. Steel inserts used to provide a more
wear-resistant threaded hole in soft tooling elements, such as aluminum tool bases.
Throw. The radial movement of a cam about its
mounting point or hole.
TIR. The acronym for total indicator reading.
Toggle Clamp. A commercially available style of
clamping device that uses a series of levers to
operate and hold the position of the clamp.
Tolerance. The amount of variation, or deviation,
permitted in the size of a part.
Tombstone. A commercially available tooling block
that is mounted on machining centers and similar
machine tools to provide multiple mounting surfaces for workholders.
Tool Body. The major structural element of a jig or
fixture.
Tool Design. The science, or process, of designing
jigs, fixtures, or any other special-purpose tools
required for manufacturing purposes.
Tool Drawings. The mechanical drawings made and
used to build special-purpose tools.
Tool Force. The force exerted against a workpiece
by the cutting tool.
Tool Steel. A type of alloy steel made to very close
specifications and primarily used for tools or
similar types of parts.
Tooling Estimate. A management guide to the overall cost and benefit of a special-purpose tool. This
estimate shows the cost of the tool and the relative cost of the operation with the tool and with
alternate methods of manufacture.
Toolmaker. A skilled craftsman who specializes in
making the special-purpose tools required for
manufacturing.
354 GlossaryTotal Runout. The geometric characteristic that specifies a relationship between two or more concentric diameters of a part measured totally around
and across the part feature.
Toughness. The property of a material that allows it
to resist fracture from sudden loads.
Trunnion Jig. A type of jig used to accommodate
large parts that must be machined on several sides.
Tumble Jig. A form of jig that completely encloses
the part being machined. It is also called a box jig.
Unilateral Tolerances. Tolerance values that may
go only in a single direction, either plus or minus,
from the basic size.
U.S. Customary System. The inch-based system of
linear measurement.
Urethane. A nonmetallic tooling material used for
applications in which the tool must be nonmarring.
Vacuum Chuck. A mechanical workholder that uses
the force of a vacuum to hold a nonporous workpiece. This chuck may be used on any ferrous,
nonferrous, or nonmetallic material that will hold
a vacuum.
Vee Locators. Locating devices that have a V form.
They are very useful for cylindrically shaped parts.
Vise-Jaw Tooling. Special-purpose jigs and fixtures
made from blanks that are the same dimensions as
those of the replaceable jaws of a machine vise.
Washers. Mechanical fastening devices used under
nuts, screws, and bolts either to prevent damage
when the fastener is tightened or to provide a
mechanical lock to prevent loosening.
Wear Block. Any device used to prevent premature
wear to any surface of a workholder.
Wear Resistance. The ability of a material to resist
wear or abrasion.
Wedge Clamp. A type of clamping device that uses
a wedge to activate and hold the clamped part.
Wedge. A mechanical clamping device that uses the
principle of the inclined plane. The two primary
variations of the wedge are flat and conical.
Workholder. A term used to describe jigs and fixtures.
Glossary 355Aluminum Association
750 Third Avenue
New York, NY 10017
American Iron and Steel Institute
1000 16th Street NW
Washington, DC 20036
American National Standards Institute
1430 Broadway
New York, NY 10018
American Society of Mechanical Engineers
United Engineering Center
345 East 47th Street
New York, NY 10017
American Society for Metals
9513 Kinsman Road
Metals Park, OH 44073
National Machine Tool Builders Association
7901 Westpark Drive
McLean, VA 22101
National Tool, Die & Precision Machining
Association
9300 Livingston Road
Washington, DC 20022
Society of Manufacturing Engineers
One SME Drive
P.O. Box 930
Dearborn, MI 48128
Professional OrganizationsNote: Boldface numbers indicate illustrations and
tables.
5C collets, 275, 276
absolute programming, numerically controlled
(NC) machines and, 307–308, 307
accessories, clamping and workholding, 61–62, 64
accumulators, power (hydraulic/pneumatic)
clamps and, 234
accuracy requirements, 101, 102
adapter ring, part drawing and production
plan, 166
adjustable ball lock jig pins, 82–83, 83
adjustable stop locators, 35, 35, 36
adjustable supports, 28, 28, 29
adjusting blocks, 25, 25
air assisted power (hydraulic/pneumatic) clamps,
232–234, 233
AISI tool steel identification, 332–334, 333, 334
alignment pins, 80, 80
allowance, 90, 121, 122
alloy steels, 331–332
alloys, 330–332, 335–336
aluminum, 65, 334, 334, 335
American Society for Testing Materials (ASTM),
335–336
angle plate fixture, 13–14, 17, 194–203
clamping part in, 199, 199
locating part in, 196–199, 199
tool body design in, 199–200, 200
angle plate jig, 11–12, 12, 189–194
bushing location in, 193–194, 195
designing, 191–194
indexing part in, 193
locating, supporting, clamping part in, 193, 194
supporting, 189, 190
tool body construction, 189, 190
tool body design, 194
angle plate tool body, 116
ANSI Y14.5M-1994 dimensioning standard, xiii
assembly drawings, 109, 110, 111
automatic bar feeder, 286
automatic sequencing, power
(hydraulic/pneumatic) clamps and, 237
Automatic Toggle Clamp, 299, 299, 300
auxiliary clamp, 208
auxiliary support, 191
axes, numerically controlled (NC) machines and,
304, 305
Indexball element clamps, 248–250, 250, 251
ball lock jig pins, 82–83, 83
Ball Lock mounting system, 299, 300, 301, 302
ball plunger, 194, 195
basic dimension, 131, 132
Bi Lok Machine Vise, 285, 289
bismuth alloys, 336
block locators, 218, 218
bolts, 75–76, 76
boring jigs, 8, 9
box jig, 9, 12, 13, 208–212, 210
break-even point calculation, 94–95
brittleness, 330
built-up tool bodies, 65–66
burr clearance, construction principles and, 72
bushing location, 29, 30, 221–222, 339
angle plate jig, 193–194, 195
box jig, 210–212, 213
channel jig, 207–208, 208
leaf or sandwich jig, 184, 185
plate jig and, 173–176, 176
table jig, 180
template jigs and, locating in, 142–145, 144, 145
butt plate, 143, 147, 152, 157
cables, to attach workbody to pins, 81, 82
cam action clamps, 48–49, 48, 49, 154, 158–165
cam edge clamps, 248, 249
cap screws, 73–74, 74
carbide bushings, 71
carbon steel, 330–331
Cartesian coordinate system, numerically
controlled (NC) machines and, 305–307, 307
case hardening, 330
cast chuck plates, 59, 60
cast iron, 65, 330
cast parts, 320, 320
cast section, 154, 155
cast tool bodies, 65
cast-bracket materials, 66, 66
castings, 271
challenges of tool designer, 3–6
channel jig, 12, 13, 204–208, 204
chuck jaws, 269–271, 270
chucks, 53, 53
chucks and chucking accessories, 269–275
circular plate template jigs, 140–141, 141
Clamp Chuck System, 271, 273–274, 275
clamp positioning, 41
clamping and workholding, 41–64
accessories for, 61–62, 64
angle plate fixture and, 199, 199
angle plate jig, 193
basic rules of, 41–43
box jig, 210, 212
channel jig, 205, 207
chucks and vises in, 53, 53, 54
clamp positioning in, 41
clamping forces in, 42–43, 43, 44, 45
leaf or sandwich jig, 183–184, 184
manual devices for, 45, 46
modular workholding and, 244, 246–247, 246
multiple clamping devices for, 61, 63
nonmechanical clamping in, 53–60
nuts and washers in, 45, 46
odd shape clamping in, 61
plate fixtures, 158, 160
plate jig and, 173, 175, 176
power (hydraulic/pneumatic) clamps in, 45, 46,
51, 52, 231–238, 232
remote, using power, 236–237
special clamping operations in, 60–61
table jig, 177–180, 180
tool forces in, 42
types of clamps used in, 43–53
vise-held fixtures, 154, 154
clamping forces, 42–43, 43, 44, 45
clamps, 41, 294–302
classes of jigs, 8–9
classification of fixtures, 17–19
Claw Clamp, 299, 300
clearance, bushings, 71–72, 72
closed jigs, 9
closers, 275
collet blocks, 276–277, 277
collet stops, 277–279, 277, 278
360 Indexcollets and collet accessories, 275–284
comparative analysis, 95–97, 95, 97
component libraries, CAD, 132, 134, 136
Computer Aided Design (CAD), xii, xiii, 107,
110, 112–116, 132–134, 134–135
Computer Aided Manufacturing (CAM), xi, xiii
computer numerical control (CNC), xi, 2,
304–315
conical wedge clamps, 49, 50
connector, 215
connector rod, 229
construction principles, 65–88
drill bushings in, 67–72, 68
fastening devices in, 73–86
preformed materials in, 66–67
set blocks in, 72–73, 74
tool bodies, 65–66
continuous path, numerically controlled (NC)
machines and, 308, 309
contour of spiral cam, 164, 165
controlled length collets, 279–281, 280
controlled length work stops, 280–281, 280
conversion table, SI to U.S., 345
corners, in heat treatment, 341, 341
cost analysis, 90–95
cost per part calculation, 93–94
cost work sheet, 93
counterbalance, 200
coupler, 192, 197
critical dimensions, 117–118, 118
cutters
plate fixtures, 158, 161
requirements for, type and size, 102
vise-held fixtures, 154–155
vise-jaw fixture, 226, 227
cylindrical cams, 49, 49
cylindrical locator, 207
datum reference, 122–126, 128, 129
dead length stop, 282–283, 285
dedicated workholders, 325
Demmeler modular fixturing system, welding
operations and, 260–263, 261, 262
design phase, 4
detailed drawings, 109–110, 111
detent pins, 82, 83
diameter symbol, 130, 131
diamond pin locator, 25, 27, 31, 31
dimensional difference, 207
dimensioning
basic dimension, 131, 132
dimensional differences and, 142, 144
geometric, 122–126, 265
geometrically dimensioned and toleranced,
132, 133
reference dimension, 131, 132
dimensioning tool drawings, 116–118, 117
millimeter and inch dimensioning in, 118–122,
119, 120
double-ended jig plate, 221, 221
dowel pin locators, 35, 35, 76–77, 78, 79
dowel pin systems, modular workholding and,
243–244, 245, 246
drafting sheets, standard, 121
drawings (See tool drawings)
drill bushings, 67–72, 68
burr clearance in, 72, 73
clearance, 71–72, 72
installation of, 71, 71
jig plates and, 71
drill jigs, 8–9, 10
drilling attachment, vise mounted, 288
drilling fixture attachments, vise, 284
dual-dimensioned drawings, 118–122, 119
Dunham vacuum chuck, 58, 58
duplex fixture, 15, 18
duplicate locators, 24–25, 24
eccentric cam clamps, 48–49, 49, 161–163, 163
eccentricity, in cams, 161, 163
economics of design (See also low-cost jigs and
fixtures; setup reduction for workholding),
89–99
analysis of costs in, 90–95
break-even point calculation in, 94–95
comparative analysis in, 95–97, 95, 97
Index 361cost per part calculation in, 93–94
labor expenses in, 91–93
low-cost jigs and fixtures in, 269–303
preformed materials and, 89
productivity versus tool cost, 90–91
secondary operations in, 90
simplicity in, 89
simplified drawings in, 90
standard components in, 89–90
tolerance and allowance in, 90
total savings calculation in, 94
edge clamping, 294
ejectors, 36, 36, 37
ElectraLock clamps, 59, 60
electromagnetic chucks, 54, 55, 56, 57
emergency collets, 275
enlargement ratios, 121, 121
epoxy resin, 65, 337–338
clamping and workholding, 61, 61
equalizing supports, 28, 30
ergonomics, 102–103
estimate, economics of design and, 91
expanding collets, 275, 283, 287
expanding jig pins, 83, 84
extended range bushings, 71, 71
external profile, locating, 33–36
eyebolts, 84, 85
failure of tools, heat treatment and, 341–342
fastening devices, 73–86
feature control symbols, 122, 122, 130
ferrous tool materials, 330–334
fixed heel blocks, 310
fixed limit gauges, 266, 267
fixed renewable bushings, 68–69, 69
fixed stop locators, 34, 35
fixtures, 8–20
flange rings, 41, 42
flat cams, 49
flat clamps, 294, 294
flat eccentric cam clamps, 48–49, 49
flat plate template jigs, 140, 141
flat spiral cams, 49, 49
flat surfaces, locating, 26–28
flat wedge clamps, 49
flexible manufacturing systems (FMS), xi
flush pin gauges, 265–266, 266, 267
foolproofing, 23–24, 212
collet stops for, 278–279
forged parts, 271, 320, 320
formulas, economic, 98
full indicator movement (FIM), 265
full nest, 33–34, 33
gauging fixtures, gauges, 263–266, 263, 264
geometric characteristics symbols, 122–123, 123,
124–128
geometric dimensioning and tolerancing in,
122–126, 132, 133, 265
go/no-go gauges, 266, 267
Golden Rule of workholding, 324
grain in wood, 337
grid paper, 107
Grip Strip Tooling System, 298, 298, 299
groove pin locators, 35, 35
guide block, 211, 214
guides, drawing, 112–114, 114
handholds, 84, 85
hanger bracket, 198, 201
hardness scale, 327, 328
heat dissipation, welding operations and,
260, 260
heat treatment, 330, 340–341
high-carbon steel, 331
high-rise clamps, 246–247, 246
hinge clamp, 45, 45
hoist rings, 84–85, 86
Hold-All clamp, 297–298, 298
hook clamps, 47, 47, 48
housing cover, 159, 162, 174, 178
human element in design, 102–106
Hydra Jaw, 293–294, 293
hydraulic clamps (See power
[hydraulic/pneumatic] clamps)
362 Index
economics of design (cont.)incremental programming, numerically controlled
(NC) machines and, 307–308, 307
independent clamping elements, 294–299
indexing fixture, 15, 18
indexing jig, 12–13, 14, 191
indexing parts, 193
initial design, 100–108
plate jig and, 176–177, 177
table jig, 180–181, 181
template jigs and, 145–146, 146
initial drawings, 115–116
Inserta Jaw chuck jaws, 271
inspection fixtures, 263–266
gauging, 263, 263, 264
measuring, 263–265, 264
supplement gauges and, 265–266
inspection phase, 5
installed locators, 34–35, 35
interchangeable fixture keys, 76, 76, 77
internal diameter, locating, 28–33, 30
jig pins, 77–83
jig plates, drill bushings and, 71
jigs, 8–20
just in time (JIT), xi
Knollwood Vise Adapter, 292, 293
knurled bushings, 69–70, 70
L pins, 80–82
labor expenses, 91–93
laminated materials, 338–340, 339
latch clamp, 45, 45
lathe fixture, 271, 272
lathe-radius fixture, 17
layered object manufacture (LOM), 2
layout template, 139–140, 140
lead time, 65
leaf jig, 12, 14, 171, 172, 181–184
least material condition (LMC), 127–129, 129
lever strap clamps, 43–47, 44, 45
lifting devices, 83–86
limit dimensions, 117, 117
linear bushings, 69, 69
link lever, 202
link lever, part drawing and production plan,
187, 187
locating the work, 21–38, 115
angle plate fixture and, 196–199, 199
angle plate jig, 193
box jig, 210, 212
channel jig, 205, 207
ejectors, 36, 36, 37
external profile, 33–36
flat surfaces, 26–28
internal diameter, 28–33, 30
leaf or sandwich jig, 183–184, 184
modular workholding and, 244, 246
plate fixtures, 156–158
plate jig and, 173, 175
predesign analysis in, 101–102
relieved locators in, 31, 31
setup reduction for workholding and, 317
spring stop buttons and spring-locating pins,
36–38, 37
table jig, 177, 180
template jigs and, 142, 144, 145
vise-held fixtures, 151–154, 153
vise-jaw fixture, 224, 226
vise-jaw jig, 217–219, 218, 220–221, 221
welding operations and, 258
locators positioning, 21–25, 22, 24, 82
lock, 148, 166
LOM (See layered object manufacture)
low-carbon steel, 330
low-cost jigs and fixtures, 269–303
chucks and chucking accessories, 269–275
collets and collet accessories, 275–284
specialty clamps and workholding devices,
294–302
vises and vise accessories, 284–294
low-melt alloys, clamping and workholding,
61, 62
machinability scale, 327, 329
machine handhold, 84, 85
Index 363machine reference sheet, 104–105
machine tool requirements, type and size, 102
machine vise, 216–217, 216, 217
machined nest locators, 218, 218
machining operations, type required, 101
machining operations, previous, 107
magnesium, 65, 335–336, 336
magnetic chucks, 54, 55, 56, 57
mandrels, 49, 50
manual devices for clamping and workholding,
45, 46
mass, unequal, in heat treatment, 340–341, 340
Master Jaw System, 281–283, 281
master plate system, modular workholding and,
241–242, 243
material selection, 100–101, 321–322, 327–343
ferrous tool materials in, 330–334
heat treatments and, 340–341
nonferrous tool materials in, 334–336
nonmetallic tool materials in, 336–340
properties of materials and, 327–330
specialty materials in, 338–340
Maxi-Mill vise, 285, 287, 291
maximum material condition (MMC), 127, 129
measuring fixture, 263–265, 264
mechanical treatment, 330
medium carbon steel, 331
metric conversion table, 345
millimeter and inch dimensioning, 118–122,
119, 120
milling fixture, 17
MITEE-BITE clamping system, 295–296, 296
modified angle-plate jig, 11–12, 12
modified angle-plate tooling, 189, 190
modular fixturing, 239
Modular Vise, 284–285, 289
modular workholding, 239–256, 240, 253,
254, 325
advantages for, 255
applications for, 250–255
clamping elements in, 244, 246–247, 246
constructing tooling for, 252–255
dowel pin systems in, 243–244, 245, 246
elements of, 253
locating and supporting elements in, 244, 246
master plate system in, 241–242, 243
mounting bases and plates in, 244, 246
multipart type, 255, 255
standard elements in, 244–246
subplate systems in, 240–242, 240, 241, 242
“T”-slot systems in, 242–243, 244
tooling form for, 251
welding operations and, 260–263
welding with, 252
modular-component workholding systems, 239
Mono-Bloc clamp, 296, 297
Multi Lok Vise, 285, 290
multipart modular workholding, 255, 255
multipurpose tooling, 101, 101
multistation fixture, 15
multistation jig, 13, 16
Multivise, 284, 288
nesting locators, 33–34, 218–219, 218, 219
nesting template jigs, 141, 141
nonferrous tool materials, 334–336
nonmechanical clamping, 53–60
nonmetallic tool materials, 336–340
note taking, 107
number of pieces required, 101
numbering system for steels, 331, 332
numerically controlled (NC) machines, 304–315
axes in, 304, 305
basic operations of, 304–305, 306
Cartesian coordinate system in, 305–307, 307
computer numerical control (CNC) in, 305
continuous path systems in, 308, 309
incremental and absolute programming in,
307–308, 307
perforated tape program for, 305, 305
point to point systems in, 308, 308
programming of, 304–305, 306
retrofitted systems in, 309, 309
tooling requirements for, 309
workholders for, 309–314
nuts and washers, 45, 46, 75–76, 75, 76
364 IndexOccupational Safety and Health Administration
(OSHA), xii, 103
odd-shape clamping, 61
oil-groove bushings, 69
open jigs, 9
packing, in magnetic chucks, 54, 57
pallet decoupler unit, 233
palletized workholders, 313–314, 314
parallel blocks, 57
part and tool size relationship, 22–23, 23
part drawings, 2, 3
partial nest, 34, 34
parts lists, 92
perforated tape program for numerically
controlled (NC) machines, 305, 305
pin locators, 29, 30, 218, 218
pivoting edge clamps, 247–248, 248
plain alignment pins, 80, 80
plain angle plate tooling, 189, 190
plain plate jig, 170, 170
planes of movement, 25–26, 25
planning tool design, 2–3
plastic resin, 337–338
plastics, 338
plate fixture, 13, 16, 155–158, 158, 159
cam clamps for, 158–165
clamping part in, 158, 160
cutter location in, 158, 161
design of, 156
locating part in, 156–158
supporting part in, 158
tool drawing of, 158, 162
plate jig, 11, 11, 170–188, 170
bushing location in, 173–176, 176
clamping part in, 173, 175, 176
designing, 171–177
initial design of, 176–177, 177
locating part in, 173, 175
supporting part in, 173, 175
tool drawing of, 177, 178
pneumatic clamps (See power
[hydraulic/pneumatic] clamps)
pneumatic collet chuck, 282, 282, 283, 284
point-to-point numerically controlled (NC)
machines, 308, 308
power (hydraulic/pneumatic) clamps, 45, 46,
51, 52
accumulators in, 234
air assisted systems in, 232–234, 233
automatic sequencing in, 237
benefits of, 236
hydraulic clamps in, 234, 234
operation of, 235–236
pneumatic systems in, 234–235, 235
remote clamping using, 236–237
shop air in, 232
types of, 231–235
precast tool bodies, 67, 67
precision lathe fixture, 271, 272
precision-ground drill rod, 66
precision-ground flat stock, 66
predesign analysis, 100–102
accuracy requirements in, 101, 102
cutter requirements, type and size, 102
locating and clamping in, 101–102
machine tool requirements, type and size, 102
machining operations, type required, 101
material selection in, type and condition,
100–101
number of pieces required in, 101
sequence of operations in, 102
size and shape (overall) of part in, 100
preformed materials, 66–67, 89
press-fit bushings, 69, 69
primary burr, 72, 73
primary locator, 25, 27, 160, 212
procurement, 5
production drawings, 109–110
production plan, 2–3, 4
productivity versus tool cost, 90–91
profiling fixture, 15, 19
programming NC machines, 304–305, 306
Prohold Workholding Fixture, 274, 275, 276
projected tolerance zone (P), 129–130, 130
projection, 121–122, 122
Index 365properties of materials, 327–330
prototypes, 2
pump jig, 13, 15
purpose of tool design, 1–7
quick acting knobs, 47–48, 48
Quick-Change Kit, for Ball Lock, 302, 302
quick-release jig pins, 82
radius symbol, 130–131, 131
raised contact locator, 32, 32
reducing production steps and handling,
323–324, 324
reduction and enlargement ratios in, 121, 121
redundant locators, 151, 153
reference dimension, 131, 132
reference sheet, 104–105
referencing tool to work, 8, 9, 21
regardless of feature size (RFS), 129
relieved locators, 31, 31, 33, 151, 154
remote power clamping, 236–237
renewable bushings, 68
repeatability feature, 21
replaceable components, setup reduction for
workholding and, 319
requirements of a tool designer, 5
resins (See also epoxy resin), 337–338
restricting movement, 25–26, 27
retaining rings, 76, 76
retrofitted numerically controlled (NC) machines,
309, 309
Richlite Fibre Laminate, 338–340, 339
ring nest, 33, 33
rise, in cam clamps, 161–164, 165
rotary jig, 13
rotary table fixture, 271, 273
round pin locator, 25, 27
S.A.F.E. ball clamp, 249, 250
safety and tool design, 103–106
sandwich jig, 11, 12, 171, 172, 181–184
screw clamps, 47, 47
screw edge clamps, 247, 248
screws, 73–86
secondary burr, 72, 73
secondary locator, 25, 27, 151, 153, 160, 212
secondary operations, economics of design
and, 90
self-locking jig pins, 81–82, 82
sequence of operations, 102
serrated bushings, 69–71, 70
set blocks, 72–73, 74, 156, 224
set screws, 74, 74, 75
setup gauges (See set blocks)
setup reduction for workholding, 316–326
benefits of, 316–317
cast and forged parts in, 320, 320
locating and, 317–318
material selection and, 321–322
redesigning for, 318–319, 318, 319
reducing production steps and handling in,
323–324, 324
replaceable components in, 319
simplicity of design and, 321, 321
standardization and, 322–323, 323
tolerancing and, 317–318, 322
workholder design and, 324–325
workpiece design and, 317–320
workpiece processing and, 320–324
shank type locator, 29
shape memory alloys/actuators, 59
shear strength, 330, 330
shop air, power (hydraulic/pneumatic) clamps
and, 232
SI drawings with U.S. customary cross references,
118–119, 119
sight bracket, 225, 228
sight locators, 36, 36
simplicity of design, 89, 321, 321
simplified drawings, 90, 110–115
single jig plate, 221, 221
size and shape (overall) of part, 100
size dimensions, 117, 117
sketch development, 115–116
sketching, 107
sliding clamp, 45, 45
366 Indexslip renewable bushings, 68, 68, 195
slot clamps, 294–295, 295
slotted locator bushings, 80, 81
socket head cap screw, 74
solid supports, 28, 28
spacer bracket, 183, 186
spacer ring, 206, 209
special clamping operations, 60–61
special purpose bolts and nuts, 75–76, 76
special purpose bushings, 69, 70
specialty chucks, 271–275
specialty collet devices, 276–283
specialty materials, 338–340
specialty vises, 284–292
specific fit, 118
specifications sheet, 106
spherical diameter symbol, 130, 131
spherical locator, 32–33, 32
spherical radius, 131, 132
spindle work stop, 286
spiral cams, 161, 163–165, 164
split contact locator, 32, 32
split pins locators, 35, 35
spring stop buttons, 36–38, 37
spring-locating pins, 36–38, 37
standard components, 89–90
standard parts descriptions, 114–115, 115,
322–323, 323
statistical process control (SPC), xi
steel, 65
step chucks, 275
step locator, 193
stereolithography, 2
stops, 28
straddle-milling fixture, 17, 155, 155
straight SI drawings, 119–120, 120
strap clamp, 43–47, 44, 45, 154
strap clamp and block, 310
strap support, 220, 223
structural steel sections, 66–67, 67
subplate systems, modular workholding and,
240–242, 240, 241, 242
subplates, 310, 311
supervision, 4
supplement gauges, 265–266
supplementary symbols, 126–132, 129, 131
support and locating principles, 21–40
angle plate jig, 189, 190, 193
leaf or sandwich jig, 183–184, 184
modular workholding and, 244, 246
plate fixtures, 158
plate jig and, 173, 175
power (hydraulic/pneumatic) clamps and,
236, 237
table jig, 177–180, 180
vise-held fixtures, 154
surface condition, in heat treatment, 341, 341
swing clamps, 47, 47
Swiveljaw, 292–293, 293
symbols used in drawings, 112, 112, 122–123,
123, 124–128, 126–132, 129, 130, 131
T pins, 80, 82
“T”-slot clamps, 294–295, 295
“T”-slot systems, modular workholding and,
242–243, 244
table jig, 11, 11, 171, 171, 177–181
bushing location in, 180
design of, 177–181
initial design in, 180–181, 181
locating part in, 177, 180
supporting and clamping part in, 177–180, 180
tool drawing for, 180, 182
tacking jigs and fixtures, welding operations and,
257–258, 259
tapered locators, 30, 30
template bushings, 69, 70
template gauges, 266, 268
template jigs, 9, 10, 139–149
bushing locating in, 142–145, 144, 145
design application for, 146
design procedures for, 141–146
initial jig design in, 145–146, 146
part locating in, 142, 144, 145
tool drawing for, 146, 147, 148
templates, drawing, 112–114, 113
Index 367temporary workholders, 325
tensile strength, 330, 330
Terrific 30 clamp, 296, 297
tertiary locators, 160, 212
thermal treatment (See heat treatment)
thread inserts, 74–75, 75, 339
throw, in cam clamps, 161
toggle clamps, 49–52, 51, 259
tolerance, 22–23, 22, 90, 117, 117, 121–123, 122
geometric tolerancing in, 122–126
geometrically dimensioned and toleranced,
132, 133
projected tolerance zone (P) in, 129–130, 130
setup reduction for workholding and, 317, 322
tombstones, 310, 311
tool bodies, 65–66
tool design, 1–7
challenges of, 3–6
design phase in, 5
inspection phase in, 6
planning the design, part drawings, production
plan in, 2–3
procurement in, 5
requirements of a tool designer and, 5
supervision in, 4
tool drawings, 109–138
computers used in (See also Computer Aided
Design), 132–134
datum reference in, 122–126, 128, 129
dimensioning in, 116–118, 117
drafting sheets in, standard, 121
dual dimensioned drawings in, 118–122,
119, 120
feature control symbols in, 122, 122, 130
geometric characteristics symbols in, 122–123,
123, 124–128
geometric dimensioning and tolerancing in,
122–126, 132, 133
initial drawings in, 115–116
least material condition (LMC) in,
127–129, 129
maximum material condition (MMC) in,
127, 129
millimeter and inch dimensioning in, 118–122,
119, 120
number of views necessary in, 112
plate fixture, 158, 162
plate jig, 177, 178
projected tolerance zone (P) in, 129–130, 130
projection in, 121–122, 122
reduction and enlargement ratios in, 121, 121
regardless of feature size (RFS) in, 129
SI drawings with U.S. customary cross
references in, 118–119, 119
sketch development in, 115–116
standard parts descriptions in, 114–115, 115
straight SI drawings in, 119–120, 120
supplementary symbols in, 126–132, 129, 131
symbols used in, 112, 112
table jig, 180, 182
template jigs and, 146, 147, 148
templates, guides, CAD libraries and, 112–114,
113, 114
tolerance and allowance comparison in, 121, 122
tolerance values in, 122–123
vise-held fixtures, 155, 157
words used on, 112
tool forces, 42
tool relationships, 115
tool steel, 332–334, 333
tooling alternatives, 107
toolroom, 3, 5
torque wrenches, 310
total indicator reading (TIR), 265
total savings calculation, 94
toughness, 327
Triple Precision Mount Vise, 285, 290
trunnion jig, 13, 15
tumble jig, 12, 13
turning fixture, 271, 272
turnover type welding fixture, 259
Twin Lock Workholding System, 287–288
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