Manufacturing design and technology : Drills : Science and technology of advanced operations

K19033

Science and Technology

of Advanced Operations

“… very valuable knowledge … new procedures to nd the root causes of

tool failure with accuracy … based on the innovative concepts … the right

methodologies and practices to help … selection of the drilling system

components to manufacture high-quality products, improve the efciency

of the drilling process and development of the next generation of high￾performance (HP) drills.”

—J. C. Outeiro, Arts et Metiers ParisTech

“… explains drilling (science and technology of advanced operations) with

high quality and innovation. … a useful reference for academics, researchers,

mechanical, manufacturing, industrial engineers, and professionals familiar

with machining technology.”

—J. Paulo Davim, University of Aveiro

Features

• Defines basic concepts, terminology, and essentials of drilling

• Introduces the concept of the drilling system, formulating the systems

rules (laws) and showing the impact of the first-level system components

• Provides multiple methodologies and practical examples for the

design, manufacture, and inspection of high-productivity drills

• Covers the subject from a very basic level to the high level of scientific

results achieved to date

• Discusses common materials for making drilling tools with

exceptional depth of scientific and technical detail

In a presentation that balances theory and practice, Drills: Science and

Technology of Advanced Operations details the basic concepts, terminol￾ogy, and essentials of drilling. The book addresses important issues in

drilling operations, and provides help with the design of such operations. It

debunks many old notions and beliefs while introducing scientifically and

technically sound concepts with detailed explanations.

Manufacturing and Industrial Engineering

V I K T O R P. A S TA K H O V

Manufacturing Design and Technology

Science and Technology of

Advanced Operations

ASTAKHOV of Advanced Operations Science and Technology

Science and Technology of

Advanced Operations

Manufacturing Design and Technology Series

Series Editor

J. Paulo Davim

Drills: Science and Technology of Advanced Operations (2014)

Viktor P. Astakhov

Diamond Tools in Abrasive Machining (2014)

Mark Jackson

CRC Press is an imprint of the

Taylor & Francis Group, an informa business

Boca Raton London New York

V I K T O R P. A S TA K H O V

Science and Technology of

Advanced Operations

Manufacturing Design and Technology

CRC Press

Taylor & Francis Group

6000 Broken Sound Parkway NW, Suite 300

Boca Raton, FL 33487-2742

© 2014 by Taylor & Francis Group, LLC

CRC Press is an imprint of Taylor & Francis Group, an Informa business

No claim to original U.S. Government works

Version Date: 20130923

International Standard Book Number-13: 978-1-4665-8435-8 (eBook - PDF)

This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been

made to publish reliable data and information, but the author and publisher cannot assume responsibility for the valid￾ity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright

holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this

form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may

rectify in any future reprint.

Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or uti￾lized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopy￾ing, microfilming, and recording, or in any information storage or retrieval system, without written permission from the

publishers.

For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://

www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923,

978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For

organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged.

Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for

identification and explanation without intent to infringe.

Visit the Taylor & Francis Web site at

http://www.taylorandfrancis.com

and the CRC Press Web site at

http://www.crcpress.com

v

Contents

Preface..............................................................................................................................................xv

Acknowledgments..........................................................................................................................xxv

Author ..........................................................................................................................................xxvii

Chapter 1 Drilling System ............................................................................................................1

1.1 Fundamentals ....................................................................................................1

1.1.1 Basic Drilling Operations ....................................................................1

1.1.2 Machining Regime in Drilling Operations..........................................4

1.1.2.1 Cutting Speed .......................................................................5

1.1.2.2 Feed, Feed per Tooth, and Feed Rate ...................................5

1.1.3 Depth of Cut and Material Removal Rate............................................7

1.1.4 Cut and Its Dimensions........................................................................8

1.1.5 Selecting Machining Regime: General Idea ...................................... 10

1.1.6 Cutting Force and Power.................................................................... 13

1.1.6.1 Definition of Terms According to ISO Standard................ 13

1.1.6.2 Basis of the Cutting Force and Power Calculations ........... 13

1.2 Drilling System for HP Drills: Structure, Properties, Components,

and Failure Analysis........................................................................................ 15

1.2.1 System Concept.................................................................................. 15

1.2.2 Drilling System ..................................................................................20

1.2.2.1 Structure of the Drilling System ........................................20

1.2.2.2 Coherency Law................................................................... 21

1.2.2.3 System Objective ................................................................22

1.2.3 Case for HP Drills..............................................................................22

1.2.4 Design of Drilling Systems................................................................25

1.2.4.1 Part Drawing Analysis and Design of the Tool Layout......27

1.2.4.2 Drill Selection/Design........................................................28

1.2.4.3 Drill Material Selection...................................................... 32

1.2.4.4 HP Drill Design/Geometry Selection................................. 33

1.2.4.5 Part-Holding Fixture Design/Selection ..............................34

1.2.4.6 Metal Working Fluid .......................................................... 35

1.2.4.7 Controller............................................................................ 35

1.2.4.8 Machine Tools ....................................................................37

1.2.4.9 Tool Holders........................................................................40

1.2.5 Summary: Checklist of Requirements for the Drilling System

for HP Drilling ...................................................................................49

References .................................................................................................................. 52

Chapter 2 Tool Failure as a System Problem: Investigation, Assessment,

and Recommendations............................................................................................... 55

2.1 Traditional Notions and Approaches............................................................... 57

2.2 Failure: A System-Related Definition ............................................................. 58

2.3 Tool Failure Prime Sources.............................................................................58

vi Contents

2.4 Preparation Stage: Collecting Information......................................................59

2.4.1 Knowing That a Failure Occurs.........................................................59

2.4.2 Tool Tracking: The Tag System .........................................................59

2.4.3 Automated Tool Tracking with RFID................................................60

2.4.4 Collecting Other Supporting Information and Evidences..................63

2.4.5 Assessment of the Collected Evidences: Obvious Root Causes.........64

2.4.6 Additional Information Needed for Normal Tool Failure

Analysis........................................................................................ 68

2.4.6.1 Tool Drawing ......................................................................69

2.4.6.2 Tool Layout.........................................................................69

2.4.6.3 Tool Inspection Report .......................................................70

2.4.6.4 Part Inspection Report........................................................70

2.4.6.5 Drilling System Background Information..........................70

2.4.6.6 Additional Information if the Problem Was Solved ...........73

2.4.6.7 Tool History........................................................................73

2.4.6.8 Inventory Count and Delivery Schedule

for the Next Supply .............................................................73

2.5 Part Autopsy and Tool Reconstruction Surgery..............................................73

2.5.1 Example: Step 1—Failure Information.............................................. 74

2.5.2 Example: Step 2—Analysis of the Collected Failure Information........75

2.5.3 Example: Step 3—Sectioning the Autopsy Specimen....................... 75

2.5.4 Example: Step 4—First Microscopic Examination

of the Sectioned Part .......................................................................... 78

2.5.5 Example: Step 5—Breaking the Precut Section and Separating

Debris/Tool Fragments....................................................................... 78

2.5.6 Example: Step 6—Examining the Surface

of the Machined Hole ................................................................80

2.5.7 Example: Step 7—Reconstruction of the Bottom of the Hole

Being Drilled...................................................................................... 81

2.5.8 Example: Step 8—Reconstruction of the Drill and Root Cause

Determination.....................................................................................82

2.5.9 Example: Step 9—Archiving the Evidence and Writing

a Report................................................................................... 84

2.6 Tool Wear ........................................................................................................85

2.6.1 Background Information ....................................................................85

2.6.2 Standard Wear Assessment ................................................................88

2.6.3 Statistical Analysis of Tool Wear Curves........................................... 91

2.6.4 Common Wear Regions of Drills.......................................................99

2.6.5 Assessment of Tool Wear of HP Drills............................................ 103

2.6.6 Correlations of Drill Wear with Force Factors................................. 104

2.6.7 Assessment of Wear Resistance of Tool Materials .......................... 105

2.6.8 Real Mechanisms of Tool Wear: Pure Abrasion, Adhesion,

and Abrasion–Adhesive Wear.......................................................... 107

2.6.9 Special Wear Mechanisms: Reaction of the Cutting Tool on

Increased Cutting Speed and the Optimal Cutting Temperature..... 111

2.6.9.1 Prevailing Concept ........................................................... 111

2.6.9.2 Optimal Cutting Temperature: Makarow’s Law............... 115

2.6.10 Special Wear Mechanisms: PCD ..................................................... 116

2.6.11 Casting Defects and Tool Wear/Failure ...........................................126

2.6.12 Special Wear Mechanisms: Cobalt Leaching .................................. 130

Contents vii

2.6.13 Facts and Physics of the Wear of Tool Materials............................. 133

2.6.13.1 Need for a New Theory of Tool Wear .............................. 133

2.6.13.2 Diffusion Self-Healing of Microcracks............................ 137

References ................................................................................................................ 139

Chapter 3 Tool Materials .......................................................................................................... 143

3.1 Words of Wisdom.......................................................................................... 143

3.2 Basic Properties............................................................................................. 144

3.2.1 Wear Resistance ............................................................................... 145

3.2.2 Toughness......................................................................................... 145

3.3 High Speed Steels.......................................................................................... 147

3.3.1 Why HSSs?....................................................................................... 147

3.3.2 Brief History..................................................................................... 148

3.3.3 Common Grades of HSS.................................................................. 149

3.3.3.1 Group I: General-Purpose HSSs....................................... 150

3.3.3.2 Group II: Abrasion-Resistant HSSs.................................. 150

3.3.3.3 Group III: High Red Hardness HSSs ............................... 150

3.3.3.4 Group IV: Super HSSs...................................................... 151

3.3.4 Factors Affecting Intelligent Grade Selection of HSS..................... 151

3.3.5 Formation of Properties ................................................................... 154

3.3.5.1 Casting of HSS ................................................................. 156

3.3.5.2 Dealing with Cast Structure ............................................. 158

3.3.6 Components in HSS ......................................................................... 167

3.3.6.1 Tungsten and Molybdenum............................................... 167

3.3.6.2 Chromium......................................................................... 167

3.3.6.3 Vanadium.......................................................................... 168

3.3.6.4 Cobalt................................................................................ 168

3.3.6.5 Carbon .............................................................................. 168

3.3.6.6 Sulfur................................................................................ 168

3.3.7 Heat Treatment of HSS..................................................................... 170

3.3.7.1 Soft Annealing and Stress Relieving................................ 170

3.3.7.2 Hardening and Tempering................................................ 171

3.3.7.3 Cryogenic Treatment of HSSs .......................................... 173

3.3.8 Coating of HSS................................................................................. 175

3.4 Cemented Carbides........................................................................................ 179

3.4.1 What Is Cemented Carbide?............................................................. 180

3.4.2 Brief History..................................................................................... 180

3.4.3 Grade Classification ......................................................................... 182

3.4.3.1 Earlier Standards.............................................................. 182

3.4.3.2 Current Standard .............................................................. 183

3.4.4 Problem ............................................................................................ 186

3.4.5 Properties of Cemented Carbides..................................................... 187

3.4.5.1 Introduction Notes............................................................ 187

3.4.5.2 Groups of Properties......................................................... 188

3.4.5.3 Formation of Properties: Basics........................................ 189

3.4.5.4 Some Important Properties............................................... 190

3.4.5.5 Nondestructive Testing of Carbide Properties Using

Magnetic Measurements................................................... 197

3.4.5.6 Nanoparticle Carbides: Research and Expectations.........206

viii Contents

3.4.6 Carbide Blanks.................................................................................207

3.4.6.1 Blanks for Carbide-Tipped Drilling Tools........................208

3.4.6.2 Round Carbide Blanks...................................................... 210

3.4.6.3 Round Carbide Blanks Made of Advanced Carbides..........214

3.4.7 Coating ............................................................................................. 216

3.4.7.1 Methods of Application .................................................... 216

3.4.7.2 Coating Strategies.............................................................220

3.4.7.3 Quality Control.................................................................222

3.4.8 Cryogenic Treatment of Cemented Carbides...................................226

3.4.9 Considerations in Proper Grade Selection .......................................228

3.5 Diamond ........................................................................................................230

3.5.1 Introduction ......................................................................................230

3.5.2 Blanks for Drilling Tools: PDC and PCD Disks.............................. 231

3.5.3 Manufacturing of PCD Disks...........................................................234

3.5.3.1 Process..............................................................................234

3.5.3.2 Powder Mix.......................................................................238

3.5.4 Grain Size......................................................................................... 241

3.5.5 Interfaces..........................................................................................244

3.5.6 Thermal Stability .............................................................................245

3.5.7 PCD Grade Selection and Quality Inspection..................................250

3.5.7.1 Grade Selection Considerations........................................250

3.5.7.2 Quality Assessment of PCD Products.............................. 253

References ................................................................................................................ 255

Chapter 4 Twist and Straight-Flute Drills: Geometry and Design Components......................259

4.1 Classification .................................................................................................260

4.2 Basic Terms ...................................................................................................265

4.3 Constraints on the Drill Penetration Rate: Drill ...........................................268

4.4 Force Balance as the Major Prerequisite Feature in HP Drill

Design/Manufacturing ..................................................................................269

4.4.1 Theoretical (Intended) Force Balance..............................................269

4.4.2 Additional Force Factors in Real Tools............................................ 271

4.4.3 Resistance of a Drill to the Force Factors........................................ 272

4.4.3.1 Resistance to the Drilling Torque..................................... 273

4.4.3.2 Resistance to the Axial Force........................................... 276

4.4.3.3 Drill-Design/Process-Related Generalizations/

Considerations Related to Resistance to the Force Factors......284

4.4.3.4 Improving Drill Rigidity ..................................................287

4.4.3.5 Axial Force (Thrust)–Torque Coupling............................290

4.5 Drill Geometry .............................................................................................. 291

4.5.1 Importance of the Drill Geometry................................................... 291

4.5.2 Tool Geometry Measures to Increase the Allowable

Penetration Rate ...............................................................................292

4.5.3 Straight-Flute and Twist Drills Particularities.................................292

4.5.4 Systems of Consideration .................................................................295

4.5.5 Drilling Tool Geometry in T-hand-S: Rake and Clearance Angles...... 296

4.5.6 Drilling Tool Geometry in T-mach-S and T-use-S: Clearance Angles....... 307

4.5.7 Drilling Tool Geometry in T-mach-S and T-use-S: Rake Angles.... 314

4.5.7.1 Rake Angle in T-mach-S/T-use-S γcf Determination

According to the First Approach ...................................... 315

Contents ix

4.5.7.2 Rake Angle in T-mach-S/T-use-S γne Determination

According to the Second Approach.................................. 318

4.5.7.3 Comparison of the First and Second Approaches............ 323

4.5.7.4 Chip Breakage .................................................................. 328

4.5.8 Chisel Edge ...................................................................................... 336

4.5.8.1 General.............................................................................. 336

4.5.8.2 Case 1: The Primary Flank Is Planar and Its Width

Is Equal to or Greater than 2ao ......................................... 337

4.5.8.3 Case 2: The Primary Flank Is Planar and the Width

of the Primary Flank Is Equal to ao..................................346

4.5.8.4 Drill Flank Is Formed by Two Surfaces

(Generalization: Tertiary Flank Plane and Split Point) .... 350

4.5.8.5 Modifications of the Chisel Edge ..................................... 359

4.5.9 Point Angle and Margin...................................................................366

4.5.9.1 Axial/Radial Force Ratio .................................................368

4.5.9.2 Uncut Chip Thickness (Chip Load) and Chip Flow.........368

4.5.9.3 Exit Burr and Delamination .............................................369

4.5.9.4 Cycle Time........................................................................ 372

4.5.9.5 Back Taper........................................................................ 372

4.5.9.6 Margin and Minor Cutting Edge ...................................... 377

4.6 Drill Design Optimization Based on the Load over the Drill

Cutting Edge ............................................................................................. 384

4.6.1 Uncut Chip Thickness in Drilling.................................................... 385

4.6.2 Load Distribution over the Cutting Edge .........................................386

4.6.3 Drills with Curved Cutting Edges....................................................387

4.6.4 Generalization .................................................................................. 393

References ................................................................................................................394

Chapter 5 PCD and Deep-Hole Drills......................................................................................397

5.1 PCD Drilling Tools........................................................................................397

5.1.1 Challenges of Work Materials..........................................................397

5.1.1.1 Metal-Matrix Composites.................................................397

5.1.1.2 Polymer-Based Composite Materials ...............................399

5.1.1.3 Similarity and Differences ............................................... 401

5.1.2 PCD-Tipped Drilling Tools.............................................................. 401

5.1.3 Full-Face (Cross) PCD Drills...........................................................407

5.1.3.1 First Approach: PCD Is Sintered in a Part

of the Drill Body...............................................................407

5.1.3.2 Second Approach: PCD Segment(s) Is Brazed

into the Drill Body............................................................ 416

5.2 Deep-Hole Drills........................................................................................... 427

5.2.1 Introduction ...................................................................................... 427

5.2.2 Common Classification of Deep-Hole Machining Operations........ 428

5.2.2.1 Force Balance and the Meaning of the Term

Self-Piloting Tool.............................................................. 430

5.2.3 Additional Force Factors in Real Tools............................................ 432

5.2.4 Common Feature of SPTs: Supporting Pads.................................... 434

5.2.4.1 Locating Principle of SPTs............................................... 434

5.2.4.2 Optimal Location of the Supporting Pads........................440

5.2.4.3 Location Accuracy of the Supporting Pads......................444

x Contents

5.2.5 Gundrills .......................................................................................... 450

5.2.5.1 History .............................................................................. 450

5.2.5.2 Basic Design and Geometry ............................................. 451

5.2.5.3 Chip Breaking................................................................... 453

5.2.5.4 Common Recommendations on the Selection of Tool

Geometry/Design Parameters........................................... 456

5.2.5.5 Particularities of the Rake and Flank Geometries ........... 457

5.2.5.6 Shank ................................................................................463

5.2.5.7 Drivers ..............................................................................468

5.2.5.8 HP Gundrills and Gundrilling..........................................469

5.2.6 STS Drills......................................................................................... 491

5.2.6.1 History .............................................................................. 491

5.2.6.2 Basic Operations............................................................... 493

5.2.6.3 Basic Geometry of STS Drills..........................................496

5.2.6.4 Power and Force ............................................................... 498

5.2.6.5 Problem with the Core......................................................502

5.2.6.6 Problem with the Pressure Distribution............................504

5.2.6.7 Addressing the Problems..................................................507

5.2.7 Ejector Drills....................................................................................508

References ................................................................................................................ 520

Chapter 6 Metalworking Fluid in Drilling................................................................................ 523

6.1 Introduction ................................................................................................... 523

6.2 MWF Application Methods .......................................................................... 523

6.2.1 Flood Application.............................................................................524

6.2.2 Through-Tool MWF Application ..................................................... 526

6.2.3 Near-Dry (Minimum Quantity Lubricant) Application ................... 529

6.2.4 Application of CMWFs.................................................................... 529

6.3 High-Pressure MWF Supply: Theory, Apparatus, and Particularities

of Tool Design ............................................................................................... 529

6.3.1 Flow Rate ......................................................................................... 529

6.3.2 Pressure ............................................................................................ 530

6.3.2.1 Definition .......................................................................... 530

6.3.2.2 Pressure Measurement...................................................... 532

6.3.3 Pressure Loss in MWF Supply to the Machining Zone................... 534

6.3.3.1 Simple Tests to Understand Phenomenology

of Pressure Losses ............................................................ 534

6.3.3.2 Electrical Analogy to Comprehend the Relationship

between the Flow Rate and Pressure................................ 535

6.3.3.3 Modified Bernoulli Equation............................................ 537

6.3.3.4 Types of Flow ................................................................... 538

6.3.3.5 Viscosity ........................................................................... 538

6.3.3.6 Reynolds Number ............................................................. 539

6.3.3.7 Major Pressure Losses: Friction Factor............................ 541

6.3.3.8 Minor Losses (Losses Due to Form Resistance)..............544

6.3.3.9 Solution of the Reverse Problem....................................... 552

6.3.3.10 Practical Coolant Channel Configurations....................... 552

6.3.3.11 Pressure Loss in the Machining Zone .............................. 558

6.3.3.12 Total Pressure Loss and the Pressure Needed

to Deliver the Desirable Flow Rate...................................560

Contents xi

6.3.4 MWF Flows Management in the Bottom Clearance Space.............560

6.3.4.1 Two-Flute Drills ...............................................................560

6.3.4.2 Gundrills...........................................................................565

6.3.5 Coolant Channels Network: Ejector Effect...................................... 572

6.4 Near-Dry (Minimum Quantity Lubricant) Drilling Operations: Theory,

Apparatus, and Particularities of Tool Design .............................................. 577

6.4.1 Challenges with MWF ..................................................................... 577

6.4.2 Understanding the Subject ............................................................... 578

6.4.3 Implementation Aspects................................................................... 581

6.4.4 Aerosol (Mist) .................................................................................. 581

6.4.4.1 How Aerosol Is Generated................................................ 581

6.4.4.2 Aerosol Composition ........................................................ 582

6.4.4.3 Aerosol Parameters Control.............................................. 583

6.4.5 Classification of NDM......................................................................584

6.4.6 Cutting Tool...................................................................................... 593

6.4.6.1 Modification to the Tool Geometry .................................. 593

6.4.6.2 Modification to Design of Internal Aerosol Supply

Channels and Their Outlets (Both Shape

and Location) ..............................................................595

6.4.7 Chip Management ............................................................................596

6.5 Increasing Tool Life with CMWF.................................................................597

6.5.1 Where Does It Hurt? ........................................................................597

6.5.2 How CMWF Can Reduce Cutting Temperature.............................. 598

6.5.3 Why It Works...................................................................................599

6.6 Application of CMWFs.................................................................................599

6.6.1 Basics................................................................................................599

6.6.1.1 Work Material...................................................................600

6.6.1.2 Tool Material ....................................................................600

6.6.2 Commonly Accepted Rationale behind the Use of CMWF ............ 601

6.7 MWF Essential Parameters to Be Maintained in HP Drilling .....................602

6.7.1 Concentration ...................................................................................603

6.7.2 Water Quality ...................................................................................603

6.7.3 MWF Filtration ................................................................................604

References ................................................................................................................607

Chapter 7 Metrology of Drilling Operations and Drills........................................................... 611

7.1 Introduction ................................................................................................... 611

7.2 Standard Reference Temperature .................................................................. 613

7.3 Small-Scale Features..................................................................................... 613

7.3.1 Definition of Surface Profile, Cutoff (Sampling) Length,

and Centerline .................................................................................. 614

7.3.2 Common Characteristics of Surface Texture (Roughness)

Used in Drilling Operations............................................................. 615

7.3.3 Designation of Surface Texture (Roughness) Parameters................ 619

7.3.3.1 Basic Symbols................................................................... 619

7.3.3.2 Composition of Complete Graphical Symbol...................620

7.3.3.3 Practical Designation on Tool Drawings.......................... 623

7.3.3.4 Preferred Surface Roughness ...........................................624

7.3.3.5 Different Methods for Designating Surface Texture ........626

7.4 Large-Scale Features: Bore Tolerancing ....................................................... 627

xii Contents

7.5 Large-Scale Features: Geometrical Tolerances.............................................630

7.5.1 Concept and Standard Symbols .......................................................630

7.5.2 Definitions of Basic Terms............................................................... 631

7.5.3 Definitions of Geometrical Tolerance-Related Terms...................... 631

7.5.4 Datum Features................................................................................ 638

7.6 Bore Gaging................................................................................................... 641

7.6.1 Bore Gage Classification and Specification ..................................... 641

7.6.2 Components of Gage Accuracy........................................................642

7.6.3 Bore Gage Types..............................................................................643

7.7 Drill Metrology .............................................................................................643

7.7.1 Drilling Tool Diameter.....................................................................643

7.7.1.1 Existing Tolerances...........................................................643

7.7.1.2 Methodology to Calculate the Drilling Tool Diameter

and Its Tolerance Zone......................................................645

7.7.1.3 Assessment of the Results.................................................648

7.7.1.4 Drill Diameters in the Tool Drawing................................650

7.7.2 Shank Diameter................................................................................650

7.7.3 Overall Length/Flute Length/Shank Length ................................... 651

7.7.4 Datum...............................................................................................654

7.7.5 Runout (Straightness) .......................................................................656

7.7.5.1 Concept.............................................................................656

7.7.5.2 Importance........................................................................ 657

7.7.5.3 Method of Measurement and Tolerancing According

to Standards...................................................................... 658

7.7.5.4 Assigning in Drill Drawings.............................................660

7.7.5.5 System Runout.................................................................. 661

7.7.6 Point Angle and Lip Height..............................................................665

7.7.6.1 Point Angle Tolerances.....................................................665

7.7.6.2 Lip Height Tolerances.......................................................666

7.7.6.3 Assigning in Drill Drawings............................................. 672

7.7.7 Web Thickness, Centrality (Symmetry) of the Web,

and Flute Spacing............................................................................. 672

7.7.7.1 Web Thickness.................................................................. 672

7.7.7.2 Centrality (Symmetry) of the Web ................................... 673

7.7.7.3 Flute Spacing .................................................................... 675

7.7.8 Chisel Edge Centrality ..................................................................... 677

7.7.9 Back Taper........................................................................................ 679

7.7.10 Margin Width...................................................................................680

7.7.11 Angle of Helix.................................................................................. 681

7.7.12 Clearance Angle...............................................................................683

7.7.13 Surface Roughness...........................................................................687

7.7.14 Drill Inspection ................................................................................689

7.7.15 Dimensional Inspection (Metrological) System: Flowchart ............690

7.7.16 Dimensional Inspection (Metrological) System: Design Stage .......693

7.7.16.1 Diameter-/Length-Related Articles..................................693

7.7.16.2 Major Reference Plane......................................................695

7.7.16.3 Articles Related to the Major Cutting Edges.................... 701

7.7.16.4 Articles Related to the Chisel Edge and Its Region..........706

7.7.16.5 Articles Related to Gashes................................................709

7.7.16.6 Articles Related to the Coolant Holes .............................. 711

7.7.16.7 Dealing with Nonincluded Articles.................................. 712

Contents xiii

7.7.17 Dimensional Inspection (Metrological) System: Planning Stage .... 712

7.7.17.1 Simple Gages.................................................................... 712

7.7.17.2 Optical Microscopes/Measuring Systems........................ 713

7.7.17.3 Specialized Measuring Microscopes................................ 717

7.7.17.4 CNC Measuring Systems..................................................725

7.7.17.5 Summary .......................................................................... 733

References ................................................................................................................734

Appendix A: Axial Force, Torque, and Power in Drilling Operations................................... 735

Appendix B: Tool Material Fundamentals................................................................................ 747

Appendix C: Basics of the Tool Geometry ................................................................................ 789