ASM INTERNATIONAL ® Publication Information and Contributors Machining was published in 1989 as Volume 16 of the 9th Edition Metals Handbook With the second printing (1995), the series title was changed to ASM Handbook The Volume was prepared under the direction of the ASM Handbook Committee Authors and Reviewers • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • T.E Aaron Anocut, Inc Gary Adams Cominco Metals John Agapiou General Motors Technical Center M.S Ahmed Transfer Technology Limited (England) G Albares Technical Consultant Tom Andrew Harper Company James A Aris Rockwell International William N Ault Norton Company A Bagchi Ohio State University J Gary Baldoni GTE Laboratories Moshe M Barash Purdue University Carl Bartholed Reishauer Corporation Alan M Bayer Teledyne Vasco Abdel E Bayoumi Washington State University Bruce N Beauchesne Laser Services, Inc Bruce A Becherer Teledyne Vasco Guy Bellows Metcut Research Associates Inc Gary F Benedict Allied-Signal Aerospace Company Garrett Engine Division R.C Benn Inco Alloys International, Inc E.O Bennett University of Houston Michael Bess Aluminum Smelting & Refining Company, Inc Certified Alloys Company Hugh Bettis DoAll Company J Binns, Jr Binns Machinery Products J Binns, Sr Binns Machinery Products J T Black Auburn University Mark Bobert Technical Consultant J.F Boland Rockwell International S.P Boppana GTE Valenite F.W Boulger Technical Consultant K Brach General Electric Company J Bradley Technical Consultant José R.T Branco Colorado School of Mines R Bratt Technical Consultant R.W Breitzig INCO Alloys International James Brewer Fairfield Manufacturing Company Chris Brookes The University of Hull (England) S.T Buljan GTE Laboratories Virgil Buraczynski Besley Products Corporation Stephen J Burden GTE Valenite Corporation John H Burness The Timken Company A.C Carius General Electric Company Nick Cerwin A Finkl & Sons, Inc Harry E Chandler ASM International S Chandrasekar Purdue University • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Chao-Hwa Chang University of California, Los Angeles John D Christopher Metcut Research Associates Inc T.J Clark General Electric Company Hilary A Clouser Extrude Hone Corporation Joseph W Coniglio Gould & Eberhardt Gear Machinery Corporations John Conlon Conlon Industries, Inc S Cook LTV Aerospace Company David Cunningham General Electric Superabrasives Richard Dabeck Coral Chemical Company Dilip Dalal The Cross Company J Dalton Bardons & Oliver Timothy Danielson Chem Tronics, Inc C.V Darragh The Timken Company D.W Davies BNF Metals Technology Centre (England) Warren J Demery Sossner Tap & Tool Company Amedeo deRege Domfer Metal Powders Limited (Canada) Warren R DeVries Rensselaer Polytechnic Institute Kurt Dieme Reed Rolled Thread Die Company J Dimitrious Pfauter-Maag Cutting Tools Phil Diskins DiCo Corporation Charles A Divine, Jr AL Tech Specialty Steel Corporation R Dixon Crucible Specialty Metals Stephan Donelson Colorado School of Mines Carl J Dorsch Crucible Materials Corporation Clifford E Drake ENERPAC Group Applied Powers, Inc W Dresher International Copper Research Association D Dykehouse Technical Consultant Robert P Eichorst United Technologies Ahmad K Elshennawy University of Central Florida Dana Elza Coherent General Phil Esserkaln Kempsmith Machining Company J Richard Evans Dowty Canada Ltd (Canada) John J Fickers Los Alamos National Laboratory Michael Field Metcut Research Associates Inc M.E Finn Steltech Inc (Canada) Thomas Fisher Surftran Division Robert Bosch Corporation Donald G Flom Technical Consultant Thomas O Floyd Seco-Carboloy John E Foley S Baird Corporation David Fordanick The Cross Company Paul Frederick Dow Chemical Company Howard Friedman Fotofabrication Corporation John E Fuller Rockwell International Roland Galipeau ThermoBurr Canada (Canada) Douglas V Gallagher Rockwell International Ramesh Gandhi Alliance Tool & Manufacturing Inc Geoffrey Y Gill Muskegon Tool Industries Inc J Ginsberg Photo Chemical Machining Institute M.A Glandt Giddings & Lewis Claus G Goetzel Technical Consultant F Gorsler General Electric Company Leigh Gott Kearney & Trecker Corporation Dennis Grable The Cross Company Allan M Grant Allan M Grant & Associates • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Mikell P Groover Lehigh University Walter W Gruss Kyocera Feldmuehle, Inc J Gurland Brown University Clarence J Hagstrom Lindmark Machine Works T.E Hale Carboloy, Inc James E Hanafee Lawrence Livermore National Laboratory R Hanson Ferranti Sciaky, Inc R.E Hardesty Electrofusion Corporation S.M Harrington Thomas & Betts Corporation Derek Hartell Cleerman Machine Tool, Inc P.J Heath De Beers Industrial Diamond Division (FTY) Ltd (England) Barry Heller Teledyne Firth Sterling Gene Herron Metem Corporation Thomas Hill Speedsteel of New Jersey, Inc R.M Hooper University of Exeter (England) L Houman Axon EDM, Inc David J Howell Roll-A-Matic, Inc Fred Huscher Rockwell International Automotive Division Richard M Jacobs Consultant Services Institute, Inc J Jackson Radian Corporation E.C Jameson Transtec, Inc Ernest Jerome Zagar Inc Mark Johnson Tapmatic Corporation C.E Johnston Flow Systems, Inc K Jones Tooling Systems Inc John F Kahles Metcut Research Associates Inc Serope Kalpakjian Illinois Institute of Technology A Karl Garrett Turbine K Katbi GTE Valenite L Alden Kendall Washington State University B Klamecki University of Minnesota J.B Kohls Institute of Advanced Manufacturing Sciences, Inc Ranga Komanduri National Science Foundation Yoram Koren University of Michigan Ted Kosa Carpenter Technology Corporation William P Koster Metcut Research Associates Inc T Kozinski Precision Art Coordinators James E Krejci Keystone Threaded Products Division Theodore J Krenzer The Gleason Works Gleason Company Gerald Kusar Ajax Manufacturing Company John B Lambert Fansteel Eugene M Langworthy Aerochem, Inc L.K Lauderbaugh Rensselaer Polytechnic Institute J.A Laverick The Timken Company Frank D Leone Pitney Bowes, Inc D Levinson Taussig Associates, Inc Terry L Lievestro Lehr Precision, Inc Richard P Lindsay Norton Company Steven Lochmoeller Roton Products Inc R Luke DoAll Company Pel Lynah P R Hoffman Machine Products Gerald Makuh Weldon Tool Company Reza A Maleki Moorhead State University Stephan Malkin University of Massachusetts at Amherst • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • O Masory Texas A&M University Larry Mayer TIMET Bob McLemore The Marquardt Company Alan McMechan McDonnell Douglas Canada (Canada) Pankaj K Mehrotra Kennametal Inc Fred Meyer Precitec Corporation Thomas W McClure Balax Inc W Mihaichuk Eastern Alloys, Inc James Millar Lapmaster Division of Crane Packing Company Brian Mitchell, Sr General Broach and Engineering Company Walter R Mohn Advanced Composite Materials Corporation Frank Moravcik The Cross Company Mary Moreland Bullen Ultrasonics Inc Jonathon Morey Morey Machining Company R.A Morley Reynolds Aluminum T.O Morris Martin Marietta Energy Systems, Inc David Moskowitz Technical Consultant Bill Murphy Rodeco Company Elliot S Nachtman Tower Oil & Technology Company Steven J Neter Peterson Precision Engineering Company M Anthony Newton NItech, Inc Ronald P Ney Carpenter Technology Corporation Roger Nichting Colorado School of Mines P Niessen University of Waterloo (Canada) Bernard North Kennametal Inc Raymond J Novotny Technical Consultant J Padgett J.R Padgett Associates Ralph Panfil Davenport Machine Jeffrey T Paprocki Kearney & Trecker Corporation W Neil Peters Corning Glass Works Robert E Phillips Everite Machine Products Company R Pierce Radian Corporation Kenneth E Pinnow Crucible Metals Corporation Robert A Powell Hoeganaes Corporation D Powers Leybold Vacuum Systems, Inc J Prazniak The Timken Company Ralph E Prescott Monarch Machine Tool Company Allen Queenen Kearney & Trecker Corporation S Ramanath Norton Company V Rangarajan Colorado School of Mines M.P Ranson Inco Alloys International, Inc James Reichman Kenworth Truck Company Lawrence J Rhoades Extrude Hone Corporation C.E Rodaitis The Timken Company Harvey W Rohmiller Lodge & Shipley Division Manuflex Corporation Stuart Salmon Advanced Manufacturing Science & Technology Shyam K Samanta National Science Foundation Ron Sanders Laserdyne A.T Santhanam Kennametal Inc K Scheucher Modtech Corporation Ronald W Schneider MG Industries Scott Schneier Regal Beloit Corporation Michael Shultz Wisconsin Drill Head Company R Seely Corning Glass Works • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • W.R Sharpe Battelle Pacific Northwest Laboratories Chi-Hung Shen General Motors Technical Center T Slawson Ridge Metals Inc Ted A Slezak Armstrong-Blum Manufacturing Company William M Spurgeon University of Michigan Dearborn D.R Stashko GTE Valenite Corporation William Stasko Crucible Materials Corporation Larry E Stockline PROMESS, Inc Glenn E Stork S.S White Industrial Products Division of Pennwalt Corporation K Subramanian Norton Company Lewis Sylvia Morse Cutting Tools D Taylor Manufacturing Systems Extension Center R.A Thompson General Electric Company Thomas Thompson Badger Meter Company P Tierney Kennametal Inc Jiri Tlusty University of Florida C Treadwell Sonic-Mill Albuquerque J Tulloch Wells Saw Division Charles I Turner Kearney & Trecker Corporation William R Tyrell Branson Ultrasonics Corporation A Galip Ulsoy University of Michigan G.L Van Arsdale Battelle Pacific Northwest Laboratories M.R Van den Bergh Composites Specialties, Inc Christopher Van De Motter The Ohio Broach & Machine Tool Company Philip A Ventura The Cross Company Don Vick Ingersoll Milling Machine Company Craig E Virkus Elliott Company R.J von Gutfeld Thomas J Watson Research Center International Business Machines Charles F Walton Technical Consultant L Walton Latrobe Steel Company I Weber Technical Consultant R Terrence Webster Teledyne Wah Chang Albany W.R Welton Welton Rolled Thread Corporation Robert Werkema Technical Consultant Robert I Werner R.D Werner Company Inc Gene White Coherent General Richard F Williams Natco, Inc M.L.H Wise University of Birmingham (England) William Wonnacott Thread Grinding Service R.E Wood Lockheed Aeronautical Systems Company Hiroshi Yaguchi Inland Steel Company Patrick Yeko ENERPAC Group Applied Powers, Inc C Zimmerman GTE Valenite Emory W Zimmers, Jr Lehigh University Foreword In the 22 years since the 8th Edition Metals Handbook volume on machining was published, material removal operations have undergone dynamic changes The mechanics of the cutting process are better understood, new cutting tool materials have been developed, machine controls and computer-aided engineering have rapidly advanced, and nontraditional machining methods continue to be refined The difficult challenges faced by industry have necessitated these developments Requirements for high-strength materials and the introduction of difficult-to-machine structural ceramics, composites, and electronic components have placed new and greater demands on machining technology, and have also spurred continued research and development in material removal techniques Volume 16 of the 9th Edition describes the evolution of machining technology comprehensively, with great attention to detail and accuracy In addition to providing valuable information on recent developments, the Handbook devotes exhaustive coverage to more standard, traditional machining methods This new Volume is also the final step in the fulfillment of ASM's commitment to coverage of metalworking technology in the 9th Edition, taking its place alongside Volume (Welding, Brazing, and Soldering), Volume (Powder Metallurgy), Volume 14 (Forming and Forging), and Volume 15 (Casting) This enormous undertaking was made possible by the combined efforts of many dedicated and selfless authors and reviewers, the ASM Handbook Committee, and the ASM editorial staff Special recognition is also due to Metcut Research Associates Inc and its president, William P Koster, for permission to use tabulated data published in Volumes and of the Machining Data Handbook (3rd edition) To all the men and women who contributed to the planning and preparation of this Volume, we extend our sincere thanks Richard K Pitler President, ASM International Edward L Langer Managing Director, ASM International Preface Machining is one of the most important of the basic manufacturing processes Almost every manufactured product contains components that require machining, often to great precision Yet material removal operations are among the most expensive; in the U.S alone, more than $100 billion will be spent this year on machining These high costs put tremendous economic pressures on production managers and engineers as they struggle to find ways to increase productivity Compounding their problems is the increasing use of more difficult-to-machine materials, such as nickelbase superalloys and titanium-base alloys in aerospace applications, structural ceramics, high-strength polymers, composites (both metal-matrix and resin-matrix), and electronic materials The present Volume of Metals Handbook has been structured to provide answers to the questions and challenges associated with current machining technology Following a general introduction to machining processes, major sections containing 78 articles cover all aspects of material removal Much of this material is new In fact, 30 articles in this Volume were not included in its 8th Edition predecessor Noteworthy are the articles that have been added to describe the mechanics of the cutting process and advances in new materials, new processes, new methods of machine control, and computer-aided engineering The first Section of the Handbook reviews the fundamentals of the machining process Included are articles describing the mechanics of chip formation, the forces, stresses, and power at the cutting tool, the principles of tool wear and tool life, and the relationship between cutting and grinding parameters and surface finish and surface integrity In the following Section, extensive data are provided on the applications, advantages and limitations, properties, tool geometries, and typical operating parameters for seven classes of tool materials: high-speed tool steels (both conventional wrought and powder metallurgy), cast cobalt alloys, cemented carbides, cermets, ceramics, and ultrahard tool materials (polycrystalline diamond and cubic boron nitride) Recent developments in wear-resistant coatings that are applied on high-speed steel, carbides, and ceramics are also discussed The third Section focuses on cutting and grinding fluids their functions, selection criteria, and application Coverage of proper maintenance procedures (storage, handling, recycling, and disposal) and the toxicology and biology associated with cutting and grinding fluids is included The next Section contains 21 articles that summarize the process capabilities, machines, cutting parameters and variables, and applications of traditional chip removal processes, such as turning, drilling, and milling Advanced tooling used in multiple-operation machining, proper tool fixturing, and tool condition monitoring systems are also discussed, along with computer numerical controlled machining centers, flexible manufacturing systems, and transfer machines Although near net shape technology, including a greater use of precision casting, powder metallurgy, and precision forging, has lessened the need for some traditional machining operations, abrasive machining is being employed to a greater extent than in the past The fifth Section of the Handbook examines the principles, equipment, and applications of grinding, honing, and lapping as well as recent developments in super-abrasives, used for precision grinding of difficultto-machine and/or brittle materials The sixth Section looks at a variety of nontraditional machining methods that not produce chips or a lay pattern in the surface Mechanical, electrical, thermal, and chemical nontraditional techniques are described Applications of these methods are emphasized, with practical examples involving nontraditional machining of metals, ceramics, glasses, plastics, and electronic components The next Section describes high-speed and high removal rate processes that have been developed to dramatically increase productivity The effects of high-speed processing on chip formation and tool wear are discussed, along with materials that are being machined using these processes The eighth Section introduces the reader to two of the most rapidly developing and important areas in machining technology: machine controls and computer applications Although the basic configurations of many machine tools have not changed significantly, the advent of numerical control and adaptive control has substantially improved manufacturing productivity and workpiece quality Machine controls and the integration of CAD/CAM technology into machine tools are described in articles written with the engineer, not the software expert, in mind The last Section of the Handbook covers specific machining practices for 23 different metal systems, including all structural alloy systems, and relates the latest information on such topics as powder metals, metal-matrix composites, and honeycomb structures Machining parameters (speeds, feeds, depth-of-cut, etc.) and the influence of microstructure on machinability are described in detail Coverage includes difficult-to-machine aerospace alloys and high-silicon cast aluminum alloys, as well as materials such as beryllium and uranium that require special considerations during machining Finally, an article on machinability test methods examines various types of tests used to study cutting tool and workpiece machining characteristics Much of the credit for the content and organization of this Handbook must be given to the Steering Committee that worked with the ASM staff during the early stages of the project This group includes Professor George E Kane, Lehigh University; Dr William P Koster, Metcut Research Associates Inc.; Dr Ranga Komanduri, National Science Foundation; Dr Richard P Lindsay, Norton Company; Mr Gary F Benedict, Allied-Signal Aerospace Company, Garrett Engine Division; and Mr Michael E Finn, Stelco Inc We are also indebted to the officers of the Society of Carbide and Tool Engineers for their assistance in the planning of the Volume Finally, we gratefully acknowledge the countless hours of time and expertise loaned to the project by the nearly 200 authors and reviewers Without the collective efforts of all these individuals, the successful completion of this Handbook would not have been possible The Editors General Information Officers and Trustees of ASM International (1988-1989) Officers • • • • Richard K Pitler President and Trustee Allegheny Ludlum Corporation (retired) Klaus M Zwilsky Vice President and Trustee National Materials Advisory Board Academy of Sciences William G Wood Immediate Past President and Trustee Kolene Corporation Robert D Halverstadt Treasurer AIMe Associates Trustees • • John V Andrews Teledyne Allvac Edward R Burrell Inco Alloys International, Inc National • • • • • • • • Stephen M Copley University of Southern California H Joseph Klein Haynes International, Inc Gunvant N Maniar Carpenter Technology Corporation Larry A Morris Falconbridge Limited William E Quist Boeing Commercial Airplane Company Charles Yaker Howmet Corporation Daniel S Zamborsky Consultant Edward L Langer Managing Director ASM International Members of the ASM Handbook Committee (1988-1989) • • • • • • • • • • • • • • • • • • • • • • • • • Dennis D Huffman (Chairman 1986-; Member 1983-) The Timken Company Roger J Austin (1984-) ABARIS Roy G Baggerly (1987-) Kenworth Truck Company Robert J Barnhurst (1988-) Noranda Research Centre Peter Beardmore (1986-) Ford Motor Company Hans Borstell (1988-) Grumman Aircraft Systems Gordon Bourland (1988-) LTV Aerospace and Defense Company Robert D Caligiuri (1986-) Failure Analysis Associates Richard S Cremisio (1986-) Rescorp International, Inc Gerald P Fritzke (1988-) Metallurgical Associates J Ernesto Indacochea (1987-) University of Illinois at Chicago John B Lambert (1988-) Fansteel Inc James C Leslie (1988-) Advanced Composites Products and Technology Eli Levy (1987-) The De Havilland Aircraft Company of Canada Arnold R Marder (1987-) Lehigh University John E Masters (1988-) American Cyanamid Company L.E Roy Meade (1986-) Lockheed-Georgia Company Merrill L Minges (1986-) Air Force Wright Aeronautical Laboratories David V Neff (1986-) Metaullics Systems Dean E Orr (1988-) Orr Metallurgical Consulting Service, Inc Ned W Polan (1987-) Olin Corporation Paul E Rempes (1986-) Williams International E Scala (1986-) Cortland Cable Company, Inc David A Thomas (1986-) Lehigh University Kenneth P Young (1988-) AMAX Research & Development Previous Chairmen of the ASM Handbook Committee • • • • • • • • • • • • • • R.S Archer (1940-1942) (Member, 1937-1942) L.B Case (1931-1933) (Member, 1927-1933) T.D Cooper (1984-1986) (Member, 1981-1986) E.O Dixon (1952-1954) (Member, 1947-1955) R.L Dowdell (1938-1939) (Member, 1935-1939) J.P Gill (1937) (Member, 1934-1937) J.D Graham (1966-1968) (Member, 1961-1970) J.F Harper (1923-1926) (Member, 1923-1926) C.H Herty, Jr (1934-1936) (Member, 1930-1936) J.B Johnson (1948-1951) (Member, 1944-1951) L.J Korb (1983) (Member, 1978-1983) R.W.E Leiter (1962-1963) (Member, 1955-1958, 1960-1964) G.V Luerssen (1943-1947) (Member, 1942-1947) G.N Maniar (1979-1980) (Member, 1974-1980) • • • • • • • • J.L McCall (1982) (Member, 1977-1982) W.J Merten (1927-1930) (Member, 1923-1933) N.E Promisel (1955-1961) (Member, 1954-1963) G.J Shubat (1973-1975) (Member, 1966-1975) W.A Stadtler (1969-1972) (Member, 1962-1972) R Ward (1976-1978) (Member, 1972-1978) M.G.H Wells (1981) (Member, 1976-1981) D.J Wright (1964-1965) (Member, 1959-1967) Staff ASM International staff who contributed to the development of the Volume included Kathleen M Mills, Manager of Editorial Operations; Joseph R Davis, Senior Editor; Steven R Lampman, Technical Editor; Theodore B Zorc, Technical Editor; Heather J Frissell, Editorial Supervisor; George M Crankovic, Assistant Editor; Alice W Ronke, Assistant Editor; Karen Lynn O'Keefe, Word Processing Specialist; and Jeanne Patitsas, Word Processing Specialist Editorial assistance was provided by Lois A Abel, Robert T Kiepura, Penelope Thomas, and Nikki D Wheaton The Volume was prepared under the direction of Robert L Stedfeld, Director of Reference Publications Conversion to Electronic Files ASM Handbook, Volume 16, Machining was converted to electronic files in 1999 The conversion was based on the third printing (1997) No substantive changes were made to the content of the Volume, but some minor corrections and clarifications were made as needed ASM International staff who contributed to the conversion of the Volume included Sally Fahrenholz-Mann, Bonnie Sanders, Marlene Seuffert, Gayle Kalman, Scott Henry, Robert Braddock, Alexandra Hoskins, and Erika Baxter The electronic version was prepared under the direction of William W Scott, Jr., Technical Director, and Michael J DeHaemer, Managing Director Copyright Information (for Print Volume) Copyright © 1989 by ASM International All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the written permission of the copyright owner First printing, March 1989 Second printing, March 1995 Third printing, March 1997 This book is a collective effort involving hundreds of technical specialists It brings together a wealth of information from worldwide sources to help scientists, engineers, and technicians solve current and longrange problems Great care is taken in the production of this Reprint, but it should be made clear that NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF MERCHANT-ABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE GIVEN IN CONNECTION WITH THIS PUBLICATION Although this information is believed to be accurate by ASM, ASM cannot guarantee that favorable results will be obtained from the use of this publication alone This publication is intended for use by persons having technical skill, at their sole discretion and risk Since the conditions of product or material use are outside of ASM's control, ASM assumes no liability or obligation in connection with any use of this information No claim of any kind, whether as to products or information in this publication, and whether or not based on negligence, shall be greater in amount than the purchase price of this product or publication in respect of which damages are claimed THE REMEDY HEREBY PROVIDED SHALL BE THE EXCLUSIVE AND SOLE REMEDY OF BUYER, AND IN NO EVENT SHALL EITHER PARTY BE LIABLE Fig Surface texture symbols used for drawings or specifications In this example, all values are in inches except Ra values, which are in microinches Metric values (millimeters and micrometers) are used on metric drawings Source: Ref Fig Symbols used to define lay and its direction Source: Ref Designations of Surface Roughness Figure illustrates some of the designations of surface roughness The most common method of designating surface roughness in the United States is the arithmetical average Ra, although the rms value Rq is also used The ratio between Rq and Ra varies with the manufacturing process producing the surface (Table 1) A preferred series of roughness values is given in Table Table Ratio of root mean square roughness to arithmetic average roughness Root mean square roughness Arithmetic average roughness Theoretical ratio of sine waves, Rq/Ra Actual ratios of Rq/Ra for various processes Turning Milling Surface grinding Plunge grinding Soft honing Hard honing Electrical discharge machining Shot peening Practical first approximation of Rq/Ra For most processes For honing Rq Ra 1.11 1.17 to 1.26 1.16 to 1.40 1.22 to 1.27 1.26 to 1.28 1.29 to 1.48 1.50 to 2.10 1.24 to 1.27 1.24 to 1.28 1.25 1.45 Source: Ref Table Preferred series of roughness average values (Ra) m 0.012 0.025(a) 0.050(a) 0.075 0.10(a) 0.125 0.15 0.20(a) 0.25 0.32 0.40(a) 0.50 0.63 0.80(a) 1.00 1.25 1.60(a) 2.0 2.5 3.2(a) 4.0 5.0 6.3(a) 8.0 10.0 12.5(a) 15 20 25(a) in 0.5 1(a) 2(a) 4(a) 8(a) 10 13 16(a) 20 25 32(a) 40 50 63(a) 80 100 125(a) 160 200 250(a) 320 400 500(a) 600 800 1000(a) Source: Ref (a) Recommended Surface Roughness Produced in Manufacturing Processes The predominant method of producing engineering surfaces is by a machining process, although some finished surfaces result from primary techniques such as casting, extruding, or forging Each surface-producing method has a characteristic surface roughness range, some of which are shown in Fig The finer finishes are generally produced by machining techniques Traditional machining techniques include chip removal processes (such as turning, milling, and reaming) and abrasive processes (such as grinding, polishing, buffing, and superfinishing) A variety of surface finishes can also be produced by nontraditional machining techniques such as electrical discharge machining, electrochemical machining, or laser beam machining Surface finish requirements for representative machine tool components and aircraft engine components are given in Tables and 4, respectively Table Typical surface finish requirements for machine tool components Part name (material) Quill (4145 H) End face Outside diameter Holes Inside diameter Cam (1018) Key (1018) Holder (1018) Bracket (1018) Plate (1018) Block (1018) Junction block (1018) Ball screw (4150) Keyways Outside diameter Thread diameter Ball nut (8617) Slots Diameters Holes Machining process Surface finish required, Ra m in Mill Lathe Drill Grind Grind Mill Mill Mill Mill Mill Grind 1.60 1.60 1.60 0.40 0.40-0.80 3.2 3.2 3.2 3.2 3.2 1.60 63 63 63 16 16-32 125 125 125 125 125 63 Mill Turn Grind 3.2 3.2 0.80 125 125 32 Mill Grind Drill 3.2 1.60 3.2 125 63 125 Table Typical surface finish requirements for aircraft engine components Part name and material Operation Fan disk (Ti-6Al-4V) and turbine disk (Inconel 718) Turned Ultrasonic envelope Turned General surfaces Reamed Bolt holes Broached Dovetails Mass media finished Corner breaks Compressor casing (M-152 stainless steel) Turned Flowpath (inside diameter) Milled Outside (outside diameter) Bored Vane bores Turned Flange faces High-pressure turbine blade (René·80) Tumbled Airfoil Ground Dovetail form Ground General surfaces High-pressure turbine vane X40 (cobalt base) Tumbled Airfoil, convex Tumbled Airfoil, concave Tumbled Flowpath Ground, tumbled General surfaces Turbine shaft (Inconel 718) Journals (chromium plated) Ground Reamed Bolt holes Turned General surfaces Surface finish requirements, Ra m in 1.60 1.60-3.2 0.80-1.60 0.80-1.60 0.80 63 63-125 32-63 32-63 32 1.60-3.2 3.2 1.60 1.60 63-125 125 63 63 0.80 0.80 1.1 32 32 45 0.61-0.80 1.1 0.80 0.80 24-32 45 32 32 0.40 0.80 1.60-3.2 16 32 63-125 Fan blade (Ti-6Al-4V) Airfoil, convex Airfoil, concave Dovetail Belt ground, tumbled Belt ground, tumbled Broached 0.61-0.80 0.80-1.1 0.80 24-32 32-45 32 Fig Surface roughness produced by common production methods The ranges shown are typical of the processes listed Higher or lower values can be obtained under special conditions Source: Ref Surface Roughness and Dimensional Tolerances Surface roughness is closely tied to the accuracy or tolerance of a machine component (Table 5) A close-tolerance dimension requires a very fine finish, and the finishing of a component to a very low roughness value may require multiple machining operations For example, a 3.2 m (125 in.) surface roughness can be produced by milling or turning, while a very fine (low roughness value) surface would require grinding or additional subsequent operations, such as honing, superfinishing, buffing, or abrasive flow Therefore, specifying very fine finishes will normally result in increased costs (Table 5.) Table Classification of machined surface finishes Class Roughness, Ra Super finish Polish Ground Smooth Fine Semifine Medium Semirough Rough Cleanup m 0.10 0.20 0.40 0.80 1.60 3.2 6.3 12.5 25 50 in 16 32 63 125 250 500 1000 2000 Suitable for tolerance of plus or minus mm in 0.0125 0.0005 0.0125 0.0005 0.025 0.001 0.050 0.002 0.075 0.003 0.100 0.004 0.175 0.007 0.330 0.013 0.635 0.025 1.25 0.050 Typical method of producing finish Approximate relative cost to produce Ground, microhoned, lapped Ground, honed, lapped Ground, lapped Ground, milled Milled, ground, reamed, broached Ground, broached, milled, turned Shaped, milled, turned Milled, turned Turned Turned 40 35 25 18 13 Theoretical Surface Roughness Produced by Milling and Turning Tools It is possible to calculate the theoretical surface roughness profile produced by milling cutters and lathe tools Surface roughness calculations have been made for three of the most common cutting tool shapes These tool shapes (Fig 6(a) and 6(b)) are designated as Type A, a sharp-nose milling tooth, and Types B and C, which are a round tool and a tool with a nose radius, respectively Types B and C can be used for either milling (Fig 6(a)) or turning (Fig 6(b)) Calculations have been made of the theoretical surface roughness as a function of the feed, the tool radius, the end cutting edge angle (ECEA), and the side cutting edge angle (SCEA) (Fig 6(a) and 6(b)) The theoretical surface roughness obtained from these calculations represents the best finish commonly produced by that particular milling or turning tool and thus provides an indication of the minimum surface roughness possible with a designated tool shape and feed rate The actual surface roughness may be poorer, because the surface is further degraded by a built-up edge that is usually formed as a characteristic of the machining process Under some less common occurrences, a finer surface finish than the theoretical is produced because of the wear of the cutting edge that produces the finished surface; the worn tool develops a wearland that provides the tool with a wiping action, which tends to smooth out the theoretical surface irregularities Surface roughness is sometimes improved in milling by providing the milling cutter with one additional finishing or wiper tooth designed to produce a broad finished machining path following the cutting action of the regular chip producing teeth in the cutter Fig 6(a) Theoretical surfaces produced in models of face milling with a sharp-nose milling tool (Type A), a round tool (Type B), and a round-nose tool (Type C) Source: Ref Fig 6(b) Theoretical surfaces produced by turning with a round tool (Type B) and a round-nose tool (Type C) Source: Ref The theoretical surface roughness produced by a face milling cutter containing teeth with a zero nose radius is plotted in Fig The theoretical surface for turning or face milling with round cutting edges is illustrated in Fig 8, and the theoretical surface roughness for turning or face milling with a radius of 0.396 mm (0.0156 in.) and various end cutting edge angles is shown in Fig Numerical tables of the theoretical roughness produced by milling and turning tools as a function of the feed, end cutting edge angle, and side cutting edge angle are provided in Ref Table gives the arithmetic roughness average, Ra, and the maximum peak-to-valley roughness height, Ry, for turning and milling Table Theoretical values for arithmetic roughness average, Ra, and maximum peak-to-valley roughness height, Ry, for turning or milling with a Type C tool Tool nose radius = 0.40 mm (0.031 in.) Feed/rev (turning) or feed/tooth (milling) mm (in.) 0.020 (0.001) 0.040 (0.002) 0.060 (0.003) 0.080 (0.004) 0.100 (0.005) 0.120 (0.006) 0.140 (0.007) 0.160 (0.008) 0.180 (0.009) 0.200 (0.010) 0.250 (0.012) 0.300 (0.014) 0.350 (0.016) 0.400 (0.018) 0.450 (0.020) 0.500 (0.025) 0.600 (0.030) End cutting edge angle 3° 5° Ra Ry Ra Ry Surface roughness, m ( in.) 6° Ra Ry 10° Ra Ry 15° Ra Ry 30° Ra Ry 40° Ra Ry 45° Ra Ry 0.03 (1.0) 0.13 (4.1) 0.28 (9.3) 0.46 (16.0) 0.65 (25.0) 0.85 (34.0) 1.1 (43.0) 1.3 (53.0) 1.5 (63.0) 1.7 (73.0) 2.2 (94.0) 2.8 (115.0) 3.4 (136.0) 3.9 (158.0) 4.5 (180.0) 5.1 (236.0) 6.3 (293.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.1 (37.0) 1.5 (50.0) 1.9 (66.0) 2.2 (82.0) 2.6 (100.0) 3.6 (136.0) 4.7 (174.0) 5.7 (213.0) 6.8 (253.0) 7.9 (294.0) 9.0 (398.0) 11.0 (506.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.3 (145.0) 5.5 (196.0) 6.9 (253.0) 8.2 (312.0) 9.6 (373.0) 13.0 (503.0) 17.0 (639.0) 21.0 (781.0) 25.0 (927.0) 29.0 (1076.0) 34.0 (1463.0) 42.0 (1865.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.2 (37.0) 1.6 (51.0) 2.1 (66.0) 2.6 (84.0) 3.2 (103.0) 4.7 (149.0) 6.3 (202.0) 7.9 (259.0) 9.6 (319.0) 11.0 (381.0) 13.0 (543.0) 17.0 (711.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.5 (145.0) 6.2 (197.0) 8.0 (257.0) 9.9 (326.0) 12.0 (403.0) 17.0 (579.0) 23.0 (771.0) 29.0 (975.0) 35.0 (1189.0) 42.0 (1410.0) 48.0 (1992.0) 62.0 (2607.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.2 (37.0) 1.6 (51.0) 2.1 (66.0) 2.6 (84.0) 3.2 (103.0) 5.1 (149.0) 7.2 (204.0) 9.5 (267.0) 12.0 (339.0) 14.0 (417.0) 17.0 (636.0) 22.0 (873.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.5 (145.0) 6.2 (197.0) 8.1 (257.0) 10.0 (326.0) 13.0 (403.0) 20.0 (582.0) 27.0 (795.0) 36.0 (1043.0) 44.0 (1318.0) 53.0 (1609.0) 62.0 (2389.0) 82.0 (3232.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.2 (37.0) 1.6 (51.0) 2.1 (66.0) 2.6 (84.0) 3.2 (103.0) 5.1 (149.0) 7.4 (204.0) 10.0 (267.0) 14.0 (339.0) 17.0 (420.0) 22.0 (665.0) 31.0 (972.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.5 (145.0) 6.2 (197.0) 8.1 (257.0) 10.0 (326.0) 13.0 (403.0) 20.0 (582.0) 29.0 (795.0) 40.0 (1043.0) 54.0 (1326.0) 69.0 (1646.0) 85.0 (2613.0) 120.0 (3842.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.2 (37.0) 1.6 (51.0) 2.1 (66.0) 2.6 (84.0) 3.2 (103.0) 5.1 (149.0) 7.4 (204.0) 10.0 (267.0) 14.0 (339.0) 17.0 (420.0) 22.0 (665.0) 33.0 (972.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.5 (145.0) 6.2 (197.0) 8.1 (257.0) 10.0 (326.0) 13.0 (403.0) 20.0 (582.0) 29.0 (795.0) 40.0 (1043.0) 54.0 (1326.0) 69.0 (1646.0) 88.0 (2613.0) 132.0 (3842.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.80 (26.0) 1.2 (37.0) 1.6 (51.0) 2.1 (66.0) 2.6 (84.0) 3.2 (103.0) 5.1 (149.0) 7.4 (204.0) 10.0 (267.0) 14.0 (339.0) 17.0 (420.0) 22.0 (665.0) 33.0 (972.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.1 (100.0) 4.5 (145.0) 6.2 (197.0) 8.1 (257.0) 10.0 (326.0) 13.0 (403.0) 20.0 (582.0) 29.0 (795.0) 40.0 (1043.0) 54.0 (1326.0) 69.0 (1646.0) 88.0 (2613.0) 135.0 (3842.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 1.7 (63.0) 2.4 (93.0) 3.1 (125.0) 3.9 (159.0) 4.6 (194.0) 5.4 (230.0) 6.2 (268.0) 8.3 (344.0) 10.0 (423.0) 13.0 (503.0) 15.0 (585.0) 17.0 (669.0) 19.0 (881.0) 24.0 (1099.0) 0.03 (1.0) 0.13 (4.1) 0.29 (9.3) 0.51 (16.0) 0.79 (26.0) 1.1 (37.0) 1.4 (50.0) 1.7 (64.0) 2.0 (79.0) 2.4 (94.0) 3.2 (126.0) 4.1 (159.0) 5.0 (192.0) 5.9 (226.0) 6.9 (261.0) 7.8 (350.0) 9.7 (441.0) 0.13 (4.0) 0.50 (16.0) 1.1 (36.0) 2.0 (64.0) 3.0 (100.0) 4.0 (144.0) 5.1 (191.0) 6.3 (242.0) 7.5 (294.0) 8.7 (349.0) 12.0 (462.0) 15.0 (581.0) 19.0 (704.0) 22.0 (830.0) 26.0 (959.0) 29.0 (1291.0) 36.0 (1634.0) 0.700 (0.035) (0.040) (0.045) (0.050) (0.060) Source: Ref 7.5 (351.0) (409.0) (468.0) (527.0) (646.0) 28.0 (1321.0) (1545.0) (1772.0) (2001.0) (2465.0) 12.0 (534.0) (628.0) (723.0) (819.0) (1013.0) 44.0 (1985.0) (2343.0) (2706.0) (3074.0) (3821.0) 14.0 (615.0) (726.0) (839.0) (953.0) (1185.0) 51.0 (2277.0) (2698.0) (3127.0) (3562.0) (4447.0) 21.0 (885.0) (1063.0) (1244.0) (1429.0) (1805.0) 76.0 (3247.0) (3906.0) (4583.0) (5274.0) (6693.0) 28.0 (1120.0) (1377.0) (1640.0) (1910.0) (2466.0) 102.0 (4124.0) (5055.0) (6020.0) (7015.0) (9080.0) 42.0 (1348.0) (1783.0) (2263.0) (2778.0) (3889.0) 158.0 (5320.0) (6940.0) (8684.0) (10542.0) (14572.0) 46.0 (1350.0) (1808.0) (2355.0) (2983.0) (4447.0) 183.0 (5370.0) (7253.0) (9456.0) (11874.0) (17356.0) 48.0 (1350.0) (1808.0) (2360.0) (3018.0) (4629.0) 192.0 (5370.0) (7253.0) (9581.0) (12273.0) (18554.0) Fig Theoretical surface roughness for a face milling cutter containing teeth with a zero nose radius Source: Ref Fig Theoretical surface roughness for turning or face milling tools with round cutting edges Source: Ref Fig Theoretical surface roughness for turning or face milling tools with a radius of 0.39 mm (0.0156 in.) and various ECEAs Source: Ref Surface Integrity The specification and manufacture of unimpaired or enhanced surfaces require an understanding of the interrelationship among metallurgy, machinability, and mechanical testing To satisfy this requirement, an encompassing discipline known as surface integrity was introduced, and it has gained worldwide acceptance Surface integrity technology describes and controls the many possible alterations produced in a surface layer during manufacture, including their effects on material properties and the performance of the surface in service Surface integrity is achieved by the selection and control of manufacturing processes, estimating their effects on the significant engineering properties of work materials Surface integrity involves the study and control of both surface roughness or surface topography, and surface metallurgy Both of these factors influence the quality of the machined surface and subsurface, and they become extremely significant when manufacturing structural components that have to withstand high static and dynamic stresses For example, when dynamic loading is a principal factor in a design, useful strength is frequently limited by the fatigue characteristics of materials Fatigue failures almost always nucleate at or near the surface of a component; similarly, stress corrosion is also a surface phenomena Therefore, the nature of the surface from both a topographical and a metallurgical point of view is important in the design and manufacture of critical hardware The importance of surface integrity is further heightened when high stresses occur in the presence of extreme environments Heat-resistant, corrosion-resistant, and high-strength alloys are used in a wide variety of such applications Typical alloys used in these applications include alloy steels with hardnesses of 50 to over 60 HRC and heat-treated alloys with strength levels as high as 2070 MPa (300 ksi) Additional materials include stainless steels, titanium alloys, and high-temperature nickel-base alloys developed for high-temperature and corrosion-resistant applications Unfortunately, the alloys suitable for high-strength applications are frequently difficult to machine The hard steels and high-temperature alloys, for example, must be turned and milled at low speeds, which tend to produce a built-up edge and poor surface finish The machining of these alloys tends to produce undesirable metallurgical surface alterations, which have been found to reduce fatigue strength Typical surface integrity problems created in metal removal operations include: • • • • • • Grinding burns on high-strength steel aircraft landing gear components Untempered martensite in drilled holes in steel components Grinding cracks in the root sections of cast nickel-base gas turbine buckets Lowering of fatigue strength of parts processed by electrical discharge machining Distortion of thin components Residual stress induced in machining and its effect on distortion, fatigue, and stress corrosion Surface Alterations The types of surface alterations associated with metal removal practices are (Ref 6): Mechanical • • • • • • • • Plastic deformations (as result of hot or cold working) Tears and laps and crevicelike defects (associated with built-up edge produced-in-machining) Hardness alterations Cracks (macroscopic and microscopic) Residual stress distribution in surface layer Processing inclusions introduced Plastically deformed debris as a result of grinding Voids, pits, burrs, or foreign material inclusions in surface Metallurgical • • • • • • • • Transformation of phases Grain size and distribution Precipitate size and distribution Foreign inclusions in material Twinning Recrystallization Untempered martensite or overtempered martensite Resolutioning or austenite reversion Chemical • • • • • • • • • Intergranular attack Intergranular corrosion Intergranular oxidation Preferential dissolution of microconstituents Contamination Embrittlement by the chemical absorption of elements such as hydrogen and chlorine Pits or selective etch Corrosion Stress corrosion Thermal • • • • Heat-affected zone Recast or redeposited material Resolidified material Splattered particles or remelted metal deposited on surface Electrical • • • Conductivity change Magnetic change Resistive heating or overheating The principal causes of surface alterations produced by machining processes are: • • • • • High temperature or high-temperature gradients developed in the machining process Plastic deformation Chemical reactions and subsequent absorption into the nacent machined surface Excessive electrical currents Excessive energy densities during processing Virtually all material removal methods produce altered surface and subsurface conditions The possible surface alterations resulting from various processes are summarized in Table The mechanically and metallurgically altered zones produced by material removal processes may also extend into the surface to a considerable depth as a function of whether roughing or finishing conditions are used in the material removal process (Table 8) ... (19 3 1- 1 933) (Member, 19 2 7 -1 933) T.D Cooper (19 8 4 -1 986) (Member, 19 8 1- 1 986) E.O Dixon (19 5 2 -1 954) (Member, 19 4 7 -1 955) R.L Dowdell (19 3 8 -1 939) (Member, 19 3 5 -1 939) J.P Gill (19 37) (Member, 19 3 4 -1 937)... (19 6 6 -1 968) (Member, 19 6 1- 1 970) J.F Harper (19 2 3 -1 926) (Member, 19 2 3 -1 926) C.H Herty, Jr (19 3 4 -1 936) (Member, 19 3 0 -1 936) J.B Johnson (19 4 8 -1 9 51) (Member, 19 4 4 -1 9 51) L.J Korb (19 83) (Member, 19 7 8 -1 983)... in 1. 60 1. 6 0-3 .2 0.8 0 -1 .60 0.8 0 -1 .60 0.80 63 6 3 -1 25 3 2-6 3 3 2-6 3 32 1. 6 0-3 .2 3.2 1. 60 1. 60 6 3 -1 25 12 5 63 63 0.80 0.80 1. 1 32 32 45 0.6 1- 0 .80 1. 1 0.80 0.80 2 4-3 2 45 32 32 0.40 0.80 1. 6 0-3 .2 16