Machining Fundamentals [10 ed.] 9781635632088

Citation preview

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•

ac 1n1n un amenia s 1OTH EDITION

by

JOHN R. WALKER

BOB DIXON

Bel Air, Maryland

Walters State Community College Morristown, Tennessee

Publisher

The Goodheart-Willcox Company, Inc. Tinley Park, IL www.g-w.com

Copyright © 2019 by

The Goodheart-Willcox Company, Inc. Previous editions copyright 2014, 2004, 2000, 1998, 1993, 1989, 1981, 1977, 1973 All rights reserved. No part of this work may be reproduced, stored, or transmitted in any form or by any electronic or mechanical means, including information storage and retrieval systems, without the prior written permission of The Goodheart-Willcox Company, Inc. Manufactured in the United States of America. Library of Congress Catalog Card Number 2017046452 ISBN 978-1-63563-208-8 1 2 3 4 5 6 7 8 9 - 19 - 23 22 21 20 19 18 The Goodheart-Willcox Company, Inc. Brand Disclaimer: Brand names, company names, and illustrations for prod ucts and services included in this text are provided for educational purposes only and do not represent or imply endorsement or recommendation by the author or the p ubl isher. The Goodheart-Willcox Company, Inc. Safety Notice: The reader is expressly advised to carefully read, understand, and apply all safety precautions and warni ngs described in this book or that might also be indicated in undertak ing the acti vities and exercises descr ibed herei n to min imize risk of personal injury or injury to others. Common sense and good judgment should also be exercised and applied to help avoid all potentia l hazards. The reader should always refer to the appropriate manufact urer's tech nical information, d irections, and recommendations; then proceed w ith care to follow specific equipment operating instructions. The reader should understand these notices and cautions are not ex haustive. The publisher makes no warranty or representation whatsoever, either expressed or implied, including but not limited to equipment, proced ures, and applications described or referred to herein, their quality, performance, merchantability, or fitness for a particular purpose. The publisher assumes no responsibility for any changes, errors, or omissions in th is book. The publisher specifically disclaims any liability whatsoever, including any d irect, indirect, incidental, consequential, special, or exemplary damages resul ti ng, in whole or in part, from the reader's use or reliance upon the information, instruct ions, procedures, warnings, cautions, applications, or other matter contained in this book. The publisher assumes no responsibility for the activities of the reader. The Goodheart-Willcox Company, Inc. Internet Disclaimer: The Internet resou rces and listings in th is Goodheart-Willcox Publisher prod uct are provided solely as a convenience to you. These resources and listings were reviewed at the ti me of publ ication to provide you with accu rate, safe, and approp riate information. Good heart-Willcox Publisher has no control over the referenced websites and, due to the dynamic nature of the Internet, is not responsible or liable for the content, products, or performance of links to other websites or resources. Coodhea rt-Willcox Publisher makes no representation, either expressed or implied, regarding the content of these websites, and such references do not constitute an endorsement or recommendation of the information or content presented. It is your responsibility to take a ll protective measures to guard against inappropriate content, viruses, or other destructi ve elements. Cove r im age: Dmitry Kalinovsky/Shutterstock.com Cover background: tomertu/Shutte•·stock.com Back cover image: Pixel B/Shutterstock.com

Library of Congress Cataloging-in-Publication Data Names: Wal ker, JolU1 R., author. I Dixon, Bob (Bob A.) Title: MachinLng fw1damenta ls I by John R. Walker, Bob Dixon. Description: lOth edition . I Tinley Park, IL: The Goodheart-Willcox Company, Inc., [2019) I h1cludes index. Identifiers: LCCN 2017046452 I ISBN 9781635632088 Subjects : LCSH: Machine-shop practice. I Machining. Classification: LCC TJ1160 .W25 2019 I DOC 671.3/5--dc23 LC record available a t https:/ / lccn.loc.gov /2017046452

Introduction Machinists are highly skilled men and women. They use drawings, hand tools, precision measuring tools, drilling machines, grinders, lathes, milling machines, and other specialized machine tools to shape and finish metal and nonmetal parts. Machinists must have a sound understanding of basic and advanced machining technology, which includes: • Proficiency in safely operating machine tools of various types (manual, automatic, and computer controlled). • Knowledge of the working properties of metals and nonmetals. • The academic skills (such as math, science, English, print reading, and metallurgy) needed to make precision layouts and machine setups.

Machining Fundamentals provides an introduction to these important areas of manufacturing technology. The text explains the "how, why, and when" of numerous machining operations, setups, and procedures. Through it, you will learn how machine tools operate and when to use one particular machine instead of another. The advantages and disadvantages of various machining techniques are discussed, along with their suitability for particular applications. Machining Fundamentals details the many common methods of machining and shaping parts to meet given specifications. It also covers more advanced processes, such as laser machining, waterjet cutting, high-energy-rate forming (HERF), cryogenics, chipless machining, electrical discharge machining (EDM), electrochemical machining (ECM), robotics, and rapid prototyping. The importance of computer numerical control (CNC) in the operation of most machine tools and its role in automated manufacturing is explored thoroughly. A new chapter expands coverage of geometric dimensioning and tolerancing (GD&T). Machining Fundamentals has many features that make it easy to read and understand. The heads in each chapter are numbered to quickly locate specific information within a chapter. A chapter outline lists all chapter heads and subheads at the beginning of each chapter. Learning objectives are also presented in the chapter opener, along with a list of selected technical terms important to understand ing the material in that chapter. Throughout the text, technical terms are highlighted in bold ita lic type as they are introduced and defined. These terms are also listed and defined in the Glossary at the end of the text. The extensive illustrations, photographs, and other visuals throughout Machining Fundanzentals clarify and reinforce machining operations, procedures, and applications. A color key is used to indicate different materials and types ofequipment. Features visually highlight and expand textual content by giving it practical value. Workplace Skills and Career Connection features introduce students to machining-related careers and the qualities employers are seeking. Green Machining features expose students to recent trends in environmentally friendly manufacturing. Each chapter closes with a chapter review containing a summary and review questions. The summary reiterates and expands on the learning objectives given in the chapter opener. Review questions reinforce key learning objectives and offer students the opportunity to check their understanding. Machining Fundamentals is a valuable guide to anyone interested in machining, since the procedures and techniques presented have been drawn from all areas of machining technology. Students will gain a strong foundation in machining to support practical skills.

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About the Authors fohn R. Walker is the author of thirteen textbooks and has written numerous magazine ar ticles. Mr. Walker completed his undergraduate studies at Millersville University and has a master's degree in Industrial Education from the University of Maryland. He taught industrial arts and vocational education for more than 32 years, including 5 years as Supervisor of Industrial Education. He also worked as a machinist for the US Air Force and as a draftsman at the US Army Aberdeen Proving Grounds.

Bob Dixon is a Professor and Head of the Engineering Technology Department at Walters State Community College in Morristown, Tennessee. Dr. Dixon holds bachelor's and master's degrees in Engineering Technology from East Tennessee State Un iversity, a master's degree in Industrial Engineering from the University of Tennessee, and a doctorate in Educational Leadership from East Tennessee State University. Prior to entering the education field, Dr. Dixon spent over 20 years in industry working in a variety of machining, manufacturing, and engineering positions. He is an ATMAE Certified Senior Technology Manager and recipient of the 2005 ATMAE Outstanding Faculty of Industrial Technology Award for Region 3.

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Reviewers The authors a nd publishe r wish to t hank t he following industry a nd teaching professio nals for t heir valuable input into the develo pment of Machining Fundatnentals. Terry Anselmo Sun Area Technical Institute Northumberland, Pennsylvania

Gottfried Georgi William Horlick High School Mount Pleasant, Wisconsin

Marte Arr eola British Columbia Institute of Tech no logy Burnaby, British Columbia

John Glenn Clinton Technical School Clinton, Missouri

George Beauchemin Bay Path Regional Vocational High School Worcester, Maryland

Howard Gray Sault College Sault Ste. Marie, Ontario

Paul Bois Milford High School and Applied Technology Center Somersworth, New Hampshire

Richard Grossen Blackhawk Technical College Cottage Grove, Wisconsin

Marl' Bosworth Southwestern Illinois College Belleville, Illinois

Garth Hansen Dixie Applied Technology College Saint George, Utah

Craig Brazil Sheridan College Oakville, Ontario

Henry Hatem Renton Technical College Carnation, Washington

Michael Buechler Santa Ana College Santa Ana, California

Troy Hayes TCAT Crossville Crossville, Tennessee

Jason S. Carpenter Tennessee College of Applied Technology Morristown, Tennessee

Michael Hilber Anoka-Hennepin Secondary Technical Education Program East Bethel, Minnesota

Dr. Chesley Chambers Floyd County College & Career Academy Cedartown, Georgia

Jere my Hodkiewicz Shawano High School Clintonville, Wisconsin

Donald Dean C-TEC Newark, Ohio

Roger Holland Minnesota State College Southeast La Crescent, Minnesota

Rose M. DeNunzio Eastfleld College, Dallas County Community College District Mesquite, Texas

Bruce Jacobs Mt. Bauer Middle School Puyallup, Washington

Bruce Dirks Owatonna High School Owatonna, Minnesota

Bart Jenkins Georgia Northwestern Technical College Rome, Georgia

David Eledge Metropolitan Community College Council Bluffs, Iowa

Stephen B. Jenldns Parkside High School and Wor-Wic Community College Salisbury, Maryland

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Mike Koppy Lake Superior College Hermantown, Minnesota

Bruce Smith Tulsa Technology Center Claremore, Oklahoma

David Laton Alabama Department of Postsecondary Education Montgomery, Alabama

Marty Sn agg Heritage High School Conyers, Georgia

Danny Lester Somerset Community College Somerset, Kentucky

Paul Sorenson Minnesota State College Southeast Winona, Minnesota

Tom Livingston e T he Pennsylvania College of Technology Williamsport, Pennsylvania

James Standing Algonquin College Ottawa, Ontario

William J. McCracken, Jr. Colorado Mesa University/Western Colorado Community College Grand Junction, Colorado

Steve Stayton Colbert County Schools Tuscumbia, Alabama

Dale Miller Lebanon County Career and Technology Center Lebanon, Pennsylvania Daniel J. Miller SUNY Canton Canton, New York Daniel Morales South Texas College McAllen, Texas Brian Nelson Dunwoody College of Technology West Saint Paul, Minnesota James Niehaus Southern Indiana Career & Technical Center Evansville, Indiana Shan Packer Central Mountain High School Howard, Pennsylvania Samuel Ray The Williamson Free School of Mechanical Trades Saint Michaels, Maryland Edward Schmidt Trenton Central High School Philadelphia, Pennsylvania Preet Singh Donna High School Pharr, Texas

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Daniel Wagner HACC, Central Pennsylvania's Community College Hegins, Pennsylvania Roger Wensink Lakeshore Technical College Sheboygan Falls, Wisconsin Olaf Wick Wisconsin Indianhead Technical College New Richmond, Wisconsin Dr. John Wren Fanshawe College, St. Thomas Campus St. Thomas, Ontario Dr. John Wyatt Mississippi State University Starkville, Mississippi Nick Yates Patterson High School Baltimore, Maryland Jim Zeleny Confederation College Thunder Bay, Ontario Andy Zwanch Johnson College Scranton, Pennsylvania

Acknowledgments The authors and publisher wou ld like to thank the following companies, organizations, and individuals for their contribution of resource material, images, or other support in the development of Machining Fundamentals.

3D Systems 3M Company

Ford Motor Co. Fowler High Precision

Alden Corp. American Foundrymen's Society

General Dynamics Corp. General Motors Corp.

American Society of Mechanical Engineers AMT-T he Association for Manufacturing Technology

Giddings & Lewis, Inc. Greenfield Industries

Autocon Technologies, Inc. Baldor

Grizzly Industrial, Inc. Haas Automation, Inc. Hardinge, Inc.

Bethlehem Steel Co. BIG Kaiser Precision Tooling Inc. Bill Hannan Bird-Johnson Company Bob Walker Bridgeport Machines, Inc. Bueh le r, a division of ITW Company C. & E. FEIN GmbH Carboloy Carl Zeiss, Inc. Carpenter Steel Co. Chicago- Latrobe

Heli-Coil Corp. Helisys, Inc. Hertel Cutting Technologies, Inc. Heule Precision Tools Hirata Corporation of America Honeywell, Inc., Industrial Automation and Control Hougen Manufacturing, Inc. Hydromat, Inc. !BAG North America IBM Iscar Metals, Inc.

Chick Machine Tool, Inc. Cincinnati Milacron

Jenoptik Jerge ns, Inc.

Cl'fCO Div., Western Atlas, Inc. Clausing Industrial, Inc.

Jet Equipment & Tools John Winter

CNC Software, Inc. Coated Abrasive Manufacturers Institute

Jones & Lamson Machine Co. Justrite Manufacturing Company K.O. Lee Co.

Cogsdill Tool Products, Inc. Compositek Corporation Dake Corporation Dapra Corporation Delcam International DoALLCo. duMont Corp. DuPont Co. Engis Corporation EZFeatureMILL- Engineering Geometry Systems Fanuc Robotics North America, Inc. Federal Products Co. FEIN Power Tools, Inc. Flow International Corp.

Kennametai KEO Cutters Kle in Tools, Inc. Komet of America, Inc. L. S. Starrett Co. Landis Div. of Western Atlas LeBlond Makino Machine Tool Co. Library of Congress, Prints & Photograph Division Light Beam Technology, Inc. Lockwood Products, Inc. Lovejoy Tool Company, Inc. Lufkin Rule Co. Lumonics Corp.

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Mack Molding Co. MAG lAS, LLC Magnaflux Corp. Mahr Federal Inc. Makita USA, Inc. Manufacturing Technology, Inc. Marposs Corp. Master Lock Co. Maswerks, Inc. Mazak Metal Powder Industries Federation MHI Machine Tool U.S.A., Inc. Microphoto, Inc. MIFCO McEnglevan Industrial Furnace Co., Inc. Millersville University Mitsubishi Materials USA Corporation Mitutoyo/ MTI Corp. Morse Tool Co. NASA National Broach & Machine Co. NEYTECH Northrop-Grumman Corp. Norton Co. NSK America O.S. Walker Co. OSG Tap & Die, Inc. PA&E Bonded Metals Division Parker-Kalon Parlee, Inc. Precision Castparts Corp. Quality Vision International, Inc. Radyne Rem Sales, Inc. Renishaw, Inc. Republic-Lagun Machine Tool Co. Revolution Tool Company Rofin-Sinar, Inc.

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Rohm and Haas Royal Products, Division of Curran Manufacturing Corporation Rush Machinery, Inc. Sandvik Coromant Co. Sharnoa Corp. Sharp Industries, Inc. SpeedFam Standard Tool Co. Stratasys, Inc. Sulzer Sunnen Products Company Tibor Machine Products Tornos-Bechler S.A. Tri-Tool, Inc. Union Carbide Corp. US Air Force US Air Force Thunderbirds US Amada, Ltd. US Army US Navy US Navy Mass Communication Specialist 2nd Class Andrea Perez Valenite, Inc. Vermont Machine Tool and the Bryant Grinder Division W.J. Savage Co. Waldes Kohinoor Inc. Webber Gage Div., L. S. Starrett Co. Webster Instrument, lnc. Weiler Corporation Westech Products Group/Gantrex Machine Tool Loaders W illiam Schotta, Millersville University Willis Machinery and Tools Corp. Wilson Instruments/Instron Corporation WMW Machinery Company, Inc. www.mini-lathe.com Yukiwa Seiko USA, Inc.

G-W Integrated Learning Solution Together, We Build Careers At Goodheart-Willcox, we take our mission seriously. Since 1921, G-W has been serving the career and technical education (CTE) community. Our employee-owners are driven to deliver exceptional learning solutions to CTE students to help prepare them for careers. Our authors and subject matter experts have years of experience in the classroom and industry. We combine their wisdom with our expertise to create content and tools to help students achieve success. Our products start with theory and applied content based on a strong foundation of accepted standards and curriculum. To that base, we add student-focused learning features and tools designed to help students make connections between knowledge and skills. G-W recognizes the crucial role instructors play in preparing students for careers. We support educators' efforts by providing time-saving tools that help them plan, present, assess, and engage students with traditional and digital activities and assets. We provide an entire program of learning in a variety of print, digital, and online formats, including economic bundles, allowing educators to select the right mix for their classroom.

Student-Focused Curated Content Goodheart-Willcox believes that student-focused content should be built from standards and accepted curriculum coverage. Standards from the National Institute for Metalworking Skills (NIMS) were used as a foundation in this text. Machining Fundamentals also uses a building block approach with attention devoted to a logical teaching progression that helps students build upon their learning. We call on industry experts and teachers from across the country to review and comment on our content, presentation, a nd pedagogy. Finally, in our refinement of curated content, our editors are immersed in content checking, securing and sometimes creating figures that convey key information, and revising language and pedagogy.

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Features of the Textbook Features are student-focused learning tools designed to help you get the most out of your studies. This v isual guide highlights t he features designed for t he textbook.

Chapter Outline provides an overview and preview of the chapter content.

learning Objectives c learly identify the knowledge and skills to be obtained when the chapter is completed.

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23 your resume when you apply for a job. Your resume should include the follow ing items: • Your fu ll name. • Your telephone number, e-mail address, and full address. Do not forget area and zip codes. (A helpful hint: Make sure your e-mail address is professional. E-mails with funny or suggestive wording may have been humorous at one time, but a prospective employer will not be amused. The same goes for greetings on your telephone voicemail. Do not disqualify yourself from an interview by displaying unprofessional behavior.) • Education and any special training. Include dates of all educational attendance. • T he types of equipment that you can safely operate. • Names of previous employers. List the places you have worked, starting with the most recent. Include the items that follow (for each previous employer): • • • •

Company name and address. Dates employed. Immediate supervisor's name. Salary or pay rate.

• Reason for leaving. • Names and addresses of references. Do not include relatives unless you have worked for them. Make sure you secure permission before using a person for a reference. Today, many job seekers specify "References available on request," instead of listing the names and addresses on the resume.

2.3.2 Social Media W ith the rise in the use of the Intemet and social media websites, many people are documenting their lives in a public fowm for everyone to see. This includes prospective employers, who regularly look for social media sites of prospective employees. Social media content can reflect both positively and negatively on any job applicant. First impressions are important, so do not disqualify yourself from consideration for a job by posting things on the Internet that will make a n employer think you lack some of the important traits that employers desire in employees. Never post anything that could be considered offensive or in poor taste. This includes making unkind comments about coworkers or former employers. Keep your professional and personal social media use separate. Some social media sites, such as Linkedln, can actually help you with your job search. Be sure to provide accurate information, and avoid exaggeration.

2.3.3 What an Employee Should Expect from Industry From the preceding sections, you have some idea of what industry expects from an employee. However, are you aware of what an employee should expect from industr y? In

Machining Fundamentals

24

Michael J. Garcia 117 Sierra Avenue Meskwaki, WI 53583

(608) 633-1234 [email protected]

Career Objective To obtain an entry-level machinist position in the manufacturing industry.

Professional Experience Minton Manufacturing, Holtan, \'V'I

August 2016-present

Machine Shop Helper • • •

Work with basic hand wols and machinery, including buffing and grinding pares. Inspect products for quality using measuring tools and machines. Perform general shop labor, including material loading and cleanup.

Putnam Supply Co., Meskwaki, WI

May 2015-August 2016

Parts CLerk • • • •

\'V'orked with customers at parts counter, checked inventory system, and obtained parts. Conducted daily and monthly inventory checks. General stocking and cleaning throughout store. Delivered and picked up pares and equipment.

Education Associate Degree in Precision Machine Technology

May 2016

Wisaka Community College • • •

•

GPA: 3.43/4.0 Coursework included precision machining, die making, CNC/CAM training, CAD drafting and solid modeling, print reading for industry, GD&T, physical metallurgy, and metrology. Obtained seven NIMS Machining Level I credentials: Measurement, Materials & Safety; Job Planning, Benchwork & Layout; Drill Press Skills I; Grinding Skills I; Manual Milling Skills l; Turning Operations: Turning Between Centers; and Turning Operations: Turning Chucking Skills. Participated in SkillsUSA chapter.

Community Service

,I

Habitat for Humanity, volunteer, summers of2014, 20 15, 2016 Meskwaki Food Bank, volunteer, 2013 - present

References Available upon request.

""

Goodheart-WJIIcox PubliSher

Figure 2-18. Your resume is an important tool that summarizes your education and training, skills, and work experience for potential employers. It should be complete, well-organized, and easy to read. Copynghl Goodheari·W·IIcox Co Inc

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Chapter 2 Careers in Machining Technology

addition to salary and benefits, what should you expect from an employer? The following are a few questions you can ask when selecting a place of employment: • Is a relatively safe and clean work area provided? Obviously, some areas can never be made as safe as others. For example, tapping a blast furnace is inherently more dangerous than working on a small lathe or drill press. • Are work areas adequately lighted, heated, and ventilated? Are noxious fumes and dust particles fi ltered from the air? • Is proper safety clothing and equipment available for all dangerous work? Safety items, such as goggles, hearing protectors, and steel-tipped safety shoes, may be provided free or at minimum cost. • Are all necessary precautions observed when hazardous materials are involved? • Is there a preventive safety program, and are safety regulations and precautions rigorously enforced?

2.3.4 Factors That Can Lead to Job Termination The following facto rs can lead to failure to get a promotion, or possibly being terminated (fired) from a job: • Alcohol or illegal drug use o n the job. • Inability or refusal to perform the work required. • Being habitually tardy or missing work repeatedly without adequate reasons. • Inability to work with supervisors or peers. • Fighting with or making threats to fellow workers or supervisors.

credentials offered for machining professionals, along with the standards associated with each credential. Machining Level I Measurement, Materials & Safety Job Planning, Benchwork & Layout Manual Milling Skills I Turning Operations: Turning Between Centers Turning Operations: Turning Chucking Skills Grinding Skills I Drill Press Skills I CNC Turning: Programming Setup & Operations CNC Milling: Programming Setup & Operations CNC Turning: Operations CNC M illing: Operations Machining Level II Manual Milling Ski lls II Turning II (manual) Drill Press Skills II Grinding Skills II CNC Milling Skills II CNC Turning Skills II EDM - Wire EDM - Plunge Machining Level III CNC Turning Skills Ill CNC Milling Skills III NIMS offers additional credentials in specialty areas such as screw machining, die-making, and machine maintenance, service, and repair. These credentia ls are intended to be follow-up certifications to the machining credentia ls.

• Inability to work as a team member. • Theft of company property, or using company resources for persona l projects without permission. • Inappropriate use of social media.

2.4 Keeping Your Skills Current T he completion of your formal schooling does not mean the end of your tra ining and study. To keep a job and advance in it, you will have to keep up-to-date with the knowledge and new skills that advanced technologies demand, Figure 2-19. Keen competition from foreign-made products and the ever-changing nature of technology make this a very real necessity. Another important consideration in maintaining a competitive edge in the marketplace is to pursue professional certifications and credentials. The National Institute for Metalworking Skills (NIMS) provides several credentialing opportunities for people working in the metalworking field, including the machine tool profession. Listed below are the Copyroght Goodheart-Willcox Co., Inc.

Chuck Raus.n/Shutterstock.com

Figure 2-19. Rapidly advancing technologies often require workers to learn new skills in order to perform t heir jobs well. This worker attended workshops provided by the manufacturer to learn how to use this electri cal discharge wire cutting machine (EDWC).

Chapter Review Summary

Review Questions

• Machining careers can be divided into fo ur main categories-semiskilled, skilled, technical, and professional-based on training, level of education, and job requirements. • Information about machining-related careers can be found through a school's career center, from instructors, the Internet, community colleges or career and technical education centers, state employment services, the armed forces, or the Department of Labor. • Employers a re looking for very specific traits in their employees, including work-related sk ills, knowledge, and ability, but also honesty, dependability, teamwork and communication, initiative, and proper grooming and dress. • Employees have the right to expect certain things from their employer, including a safe, clean workplace that is adequately lighted, heated, and ventilated; availability of proper safety clothing and equipment; and enforcement of all safety regulatio ns and precautions. • Your resume should include a ll relevant information about your education and training, skills, and work experience, as well as any credentials you have earned. • What is on your resume may get you hired, but in order to keep and advance in your chosen career it is very important to keep up-to-date with new skills and advances in technology.

Answer the following questions using the information provided in this chapter.

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1. List the four general categories of metalworking

occupations. 2. ___ workers are those who perform operations that do not require a high degree of skill or t raining. 3. The ___ worker usually starts his or her career as an apprentice. 4. Other than apprenticeship programs, where can specialized career tra ini ng be obtained? 5. Describe what a n all-around machinist is expected to do. 6. What does a layout specialist do? 7. List five areas of knowledge a part programmer should have to perform his or her job properly. 8. List the areas of study usually included in a technician's educational program. 9. What are some of the duties of a technician? 10. List t hree sources of information on metalworking occupations. 11. List five traits an employer wants in a prospective employee. 12. List five factors that can lead to rejection for employment. 13. What is a job resume? 14. Why should you prepare your resume before filling out a job application? 15. List three questions an employee should ask when selecting a place of employment. 16. What are five factors that can lead to job termination? 17. What is necessary if you want to keep your job and advance in your chosen career?

Copynght Goodheart· Willcox Co., Inc.

CHAPTER

3

Shop Safety

Chapter Outline 3.1 Safety in the Shop 3.1.1 Know the Materials 3.1 .2 Keep the Shop Clean 3.1 .3 Wear Protective Clothing and Equipment

Learning Objectives 3.1.4 Use Common Sense 3.1.5 Use Safety Aids 3.2 General Machine Safety 3.3 General Tool Safety 3.4 Fire Safety 3.5 Safety Data Sheets

After studying this chapter, you will be able to: • Explain why it is important to develop safe work habits. • Identify common shop safety procedures. • Dress in the proper safety equipment and clothing for a machine shop. • List general guidelines for machine and tool safety. • Select the appropriate fire extinguisher for a particular type of fire. • Explain the purpose and use of safety data sheets.

Technical Terms approved respirator combustible material machine shield Occupational Safety and Health Administration (OSHA)

protective clothing safety data sheet (SDS) safety equipment spontaneous combustion ventilation

Machining Fundamentals

28 hop safety is not something to be studied at the start of a training program and the n forgotte n; most accidents are caused by carelessness or by not observing safety rules. Remember this when your instructor insists on safe work practices. If you are diligent and follow instructions with care, machining operations can be safe and enjoyable. Safe work practices should become a force of habit. Since it is not possible to include every safety precaution, t he safety practices in this chapter are genera l. Safety precautions for specific tools and machines are described in the text where they apply, along with the description and operation of the equipment. Refer to Figure 3-1. Study all safety rules carefully and constantly apply them. W hen in doubt about any task, get help. Do not take chances.

S

SAFETY NOTE Throughout the text, Safety Notes are included to emphasize important tips and warn against potential hazards.

3.1 Safety in the Shop There are several general precautions you can take to work safely in the shop. Remember that the shop is a place to work. It is not a place for horseplay. A "jo ker" in a machine shop is a walking h azard to everyone. Daydreaming also increases your chance of injury. Understanding this and the other basic guidelines in this section can help you stay safe and enjoy your time in the shop.

3.1 .1 Know the Materials Do not machine a material until you know what it is and how it should be handled, and exercise extreme care when you are machining unfamiliar materials. For example, inhaling fumes or dust from some of the more advanced and exotic materials can cause serious respiratory ailments. Magnesium is another example. Magnesium chips burn with great intensity under certain conditions. Applying water to the burning magnesium chips only inten sifies the fire. Machining equipment can be damaged beyond repair and very serious burns can result.

3.1.2 Keep the Shop Clean Place metal scraps in the scrap bin. Never allow them to remain on t he bench or floor. These metal scraps can be very sharp and may cause injury if left on the bench or floor.

•

SAFETY NOTE Avoid using compressed air to remove chips and cutting oil from machines. Flying c hips can cause serious eye injuries. Also, oil that has been vaporized by the stream of air can ignite, resulting in pai nful burns and property damage.

Return solvents and oils to proper storage place after use. Wipe up spilled oil or solvent right away. If the spill area is extensive, use a n approved oil absorbent. See Figure 3-2. Place oily rags in an approved safety container. See Figure 3-3. Rags or waste used to clean machines may also have metal slivers embedded in them, posing an additional hazard. Placing them in a safety container will help ensure that they will not be used again. Dispose of the rags daily. This will minimize the possibility of spontaneous cornbustion (ignition by rapid oxidation or burning of oil without an external source of heat).

3.1.3 Wear Protective Clothing and Equipment

US Navy phOto by Mass Commumcatron Spectaltst 2nd Class Andrea Perez

Figure 3-1. None of the pilots in the Blue Angels fl ight demonstration squad would consider performing until all the plane's systems were thoroughly checked. In the same way, you shou ld never operate a machine tool until you have determ ined that it is in safe operating condition.

Dress properly for working around machinery. Severe injuries or even d eath can result if clothing, hair, or jewelry gets caught in moving parts. Avoid wearing loose-fitting clothing that could catch in machinery. A snug-fitting shop coat or apron can be worn to protect your street clothes, Figure 3-4 . Keep sleeves rolled up. Rings and other jewelry should be removed before working around machinery. If you have long h air, wear a cap or use other means of containing it. When operating a machine with a rotating spindle, do not wear gloves. If a glove gets caught in t he spindle, the operator's hand could be crushed. An approved respirator and special protective clothing must be worn when machining some materials. For jobs where dust and fumes are a hazard, also ensure that there is adequate ventilation. Machines must be fitted with effective vacuum systems as needed. Copynght Goodheart·Wtllcox Co Inc.

29

Chapter 3 Shop Safety

3MCcmpany

Figure 3-2. This worker in a manufacturing plant is using a special oil-absorbent material to wrap a leaking machine component. Note that the material, which is packaged in roll form, has also been used to soak up oi l on the machine base and floor. Wear appropriate safety equipment, Figure 3-5. In noisy areas, use earplugs or another type of hearing protection. Disposable plastic gloves will protect your hands when handling oils, cutting fluids, or solvents. Wear a dust mask when machining produces airborne particles, such as those from sand castings, plastics, and some grinding operations. An approved respirator must be worn in areas where machining operations produce a mist of oil or coolants. See Figure 3-6. Suitable personal protective equipment must also be worn when handling sharp, hot, or contaminated materials. Always protect your eyes. Wear eye protection whenever you are in the shop. Take no chances. Eyesight that has been damaged or destroyed cannot be replaced. Wear safety glasses, goggles, or face shields approved by the Occupational Safety and Health Administration (OSHA). It is good practice to have your own personal safety glasses or face shield. The cost is reasonable. Your instructor can help you determine the style best suited for your needs, Figure 3-7. If you wear glasses, special safety lenses are available that can be ground to your prescription. Your eye doctor or optician can help get them. Copynght Goodheart·W•IIcox Co. Inc.

Justrite Manufacturing Ccmpany

Figure 3-3. Oily rags used for cleaning machines or soaking up spil ls should be placed in an approved safety container like this one to minimize fire hazards. The container should be emptied dai ly and contents disposed of properly.

Millersvtlfe Un•versity

Figure 3-4. This trainee is properly dressed for the job she is doing. She is wearing approved eye protection and a snug-fitting apron. The machine was carefully checked before she began to operate it.

30

Machining Fundamentals

A Goodheart-Willcox Publisher

Figure 3-5. Wear appropriate safety equipment. Shown are approved eye protection, an apron to protect cloth ing, plastic gloves for handl ing oils and solvents, a hearing protector, earplugs, and a dust mask.

I

) B Goodheart·WIIIcox Publisher; Eldred Llm/Shutterstock.com

Figure 3-7 . A- Safety glasses are available in a number of styles. The model at left is similar to regular eyeglasses, but has "wings" at each side and on top to guard against flying particles. The goggle-style model at right fits tightly against the face and can be worn over regular eyeglasses. B-A safety face shield protects the entire face from flying debris and splatters.

3M~mpany

Figure 3-6. Whenever fine airborne mists of oil, coolant, or other materials are present, an approved respirator is required. This spray painter is wearing a respirator supplied with clean air through a tube from a central source. It is also important to use proper eye protection, such as the safety glasses worn by this worker.

for example, could cause an electric shock, severe electrical burns, or even death. Perform all lifting and moving carefully to avoid injury. When moving heavy machi ne accessories or large pieces of metal stock, always ask fo r help. The back injuries t hat can result from improper li fting are usually long-term injuries. If you have been ill and are using medication, check with your doctor or school clinic to determine whether it is safe for you to operate machinery. Even many over-thecounter cold remedies recommend that you do not operate machinery while taking the medication because of possible drowsiness.

3.1.4 Use Common Sense

3.1.5 Use Safety Aids

Other safety rules are a matter of common sense. First, know your job. It is foolish and disastrous to operate machines without first receiving proper instruction. If you are not sure what must be done, or how a task should be performed, get help. Also, use care when handling long sections of metal stock Accidentally contacting a light fixture with the stock,

Not all barriers provide physical protection from machine hazards. Awareness barriers serve to remind the operator that an area is dangerous. In its simplest form, a barrier may be nothing more than red or yellow lines painted on the floor. More complex barriers stop the machine when a light beam or electronic beam is broken by someone entering the danger area. See Figure 3-8.

Copynght Goodhean-Wollcox Co , Inc

Chapter 3

Shop Safety

31 Safety light curtain

Jenopt1k

Figure 3-8. The yellow bars on each side of the front of the safety fence are a safety light curtain. A beam of light passes from one bar to the other. If anything or anyone moves between the bars, breaking the light beam, the safety system automatically shuts off the machine.

Machine shields provide protection from flying chips and splashing cutting fluids or coolants. Many CNC machine tools are fitted with large sliding shields that cover the entire machining area, Figure 3-9.

Many different types of warning signs are used to notify workers of potential hazards, Figure 3-10. No Smoking signs must be posted in areas where flammable or combustible materials are used and stored.

3.2 General Machine Safety

Sliding shield M«k Moldmg Co.. Arlington. Vermont

Figure 3-9. Many CNC machine tools use sliding shields over the machining area to protect the machinist from flying chips and vaporized coolant.

Copyr,ghl Goodheart-Willcox Co, Inc

In addition to general safety rules, some safety guidelines are specifically designed to keep workers safe while working with machines. These guidelines include: • Never operate a machine until all guards are in place. • Keep the floor around the machine clear of oil, chips, and metal scrap. • Do not talk to anyone while you are operating a machine. You might become distracted and injure yourself, or someone else. • Never attempt to remove chips or cuttings with your hands or while the machine is operating. Use a brush, Figure 3-11. Pliers are one of the safest ways to remove long, stringy chips from a lathe. Better still, learn how to grind the cutting tool to break chips off in shorter pieces. This is explained later in the text. • Secure prompt medical attention for any cut, bruise, scratch, burn, or other injury. No matter how minor the injury may appear, report it to your instructor.

32

Machining Fundamentals

•

SAFETY NOTE Always stop the machine before making adjustments or taking measurements. Resist the urge, while the mach ine is running, to touch a surface that has been mach ined. Severe lacerations can result.

3.3 General Tool Safety Keep hand tools in good condition. Store tools in such a way that people cannot be injured while they are removing the tools from the tool panel or storage rack. In addition, follow these tool safety guidelines: • Never carry sharp-pointed tools in your pockets. When using sharp tools, lay them on the bench in such a way that you will not injure yourself when you reach for them, Figure 3-12. • Make sure tools are properly sharpened, in good condition, and fitted with suitable handles. Tools that are properly sharpened and maintained are less likely to cause injury than dull, poorly-maintained tools.

3.4 Fire Safety

Malee Nvserm!Shvtterstock.com

Figure 3-10. Signs are often used to remind students and workers to wear personal protective equipment or be alert for potential hazards.

Photo courtesy of Weiler Corporal•on

Figure 3-11 . Use a brush, not your hands, to remove accumulated chips.

Combustible materials are materials that are capable of burning. Fires are classified according to the type of combustible material that is burning, Figure 3-13. Extinguishers should have color-coded symbols to identify their appropriateness for a particular type of fire. • Class A fires . Those involving ordinary combustible materials, such as paper, wood, and textiles. They require the cooling and quench ing effect of water, or solutions containing a large percentage of water. Do not use Class A extinguishers on Class C and Class D fires.

Goocfheart-W•IIcox Pub/rsher

Figure 3-12. Arrange sharp-pointed tools on the bench in a way that they wi ll not injure you when you reach to pick them up.

Copynght Goodheart-Willcox Co, Inc

Chapter 3 Shop Safety

33

Fires

Type

Use

Class A Fires Ordinary Combustibles (Materials such as wood, paper, textiles.) Requires: cooling/quenching

Soda-acid Bicarbonate of soda solution and sulfuric acid

Okay for use on

Old

New

A Ell Class B Fires Flammable Liquids (Liquids such as grease, gasoline, oils, and paints.) Requires: blanketing or smothering Old

New

OJ

Class C Fires Electrical Equipment (Motors, switches, etc.) Requires: a nonconducting agent

Old

Class D Fires Combustible Metals (Flammable metals such as magnesium and lithium.) Requires: blanketing or smothering Old

New

!IJ

A

Direct stream at base of flame.

Not for use on

• A ~ II • II • ~] A A • ~ •

Pressurized Water Water under pressure

II

D

Okay for use on

Direct stream at base of flame.

Not for use on

Carbon Dioxide (C02 ) Carbon dioxide (C02 ) gas f\ ~ under pressure ~ ~

D

Okay for use on

Direct discharge as close to fire as possible, first at edge of flames and gradually forward and upward.

Not for use on

D

~

'----

Foam Solution of aluminum sulfate and bicarbonate of soda

Okay for use on

Direct stream into the burning material or liquid. Allow foam to fall lightly on fire.

Not for use on

D

New

erm

~

Operation

Dry Chemical

j

Multi-purpose Ordinary BC type type Okay for

A

Okay for

me me

Not okay for

Not okay for

A

0

Dry Chemical Granular-type material

Direct stream at base of flames. Use rapid leftto-right motion toward flames.

0

Okay for use on

D Not for use on

A II

•

Smother flames by scooping granular material from bucket onto burning metal.

Goodheart-WII/cox Publisher

Figure 3-13. Symbols coded by color and shape identify the four c lassifications of fire and the extinguishers that can be used on them.

Ccrynght Goodheart-Willcox Co , Ire

Machining Fundamentals

34

• Class B fires. Flammable liquid and grease fires require the blanketing or smothering effects of dry chemicals or carbon dioxide. • Class C fires. Electrical equipment fires require nonconducting extinguishing agents that will smother the flames. Do not use Class A extinguishers on electrical fires. • Class D fires. Extinguishers conta ining heat-absorbing dry powder are used on flammable metals, such as magnesium and lithium. Do not use Class A extinguishers on flammable metal fires. Know what to do in case of a fire. Be familiar with the location of your building's fire exits and how they are opened. Be aware of alternate escape routes. Thin k before acting. lt costs nothing, and you may be saved from painful injury that could result in a permanent disability. In some situations, students are trained in the use of fire extinguishers by the local fire department. lf you are one of those students, make sure that you know where the fire extinguishers are located. lf you have not received such training, get out of the fire area immediately. Fire blankets are sometimes an appropriate alternative to fire extinguishers. Fire blankets intended for industrial applications are generally made of wool, and are often chemically treated with a flame retardant fluid. They can be used on any type of fire where oxygen is needed to maintain the flame, because the blanket deprives the fire of oxygen, if placed properly. These blankets are particularly useful in smothering small fires that can be completely covered with the blanket, such as a fire contained inside a pan.

In some cases, fire blankets are the preferred method of putting out a fire. For example, fire extinguishers can spread out the fuel source, if not properly applied, and make a small fire into a larger one. A fire blanket can cover such a fire and extinguish it more effectively. Also, using chemical fire extinguishers on a person can pose serious health risks when the burns are exposed to the chemicals. If inhaled, the chemical from a fire extinguisher can be even more hazardous, even deadly. Fire blankets can be wrapped around a person whose clothing is on fire to extinguish the fire quickly.

0

GREEN MACHINING

Green Fire Safety Fire safety is a concern in any machine shop, especially those that use flammable oi l-based machining fluids. Recent advances in automated manufacturing have improved the manufacturing process but may leave combustible material and expensive equipment unattended. To protect against fires, some machine shops use on-machine fire suppression systems. These systems are set up to automatical ly detect fire and release a chemical fire extinguishi ng agent. Trad itiona l fire extinguishers contain halon, a chem ical that can cause ozone depletion when released into the atmosphere. New potassium-based extingu ish ing agents are more environmentally friendly. They do not cause ozone depletion, are nontoxic, and are easier for shop workers to clean up.

Staying Safety Conscious Safety on the job is everyone's responsibility. Many workplace accidents occur because of careless behavior. Often poor attitudes can cause unsafe behavior, too. Common causes of accidents include the following: • Taking chances. • Showing off. • Forgetting safety details. • Disobeying company rules. • Daydreami ng. • Losing your temper. • Falling asleep. Practicing good safety habits is essentia l for preventing accidents and injuries on the job. A healthy worker is more alert and less likely to make accident-prone mistakes. Knowing how to use machines and tools properly is the responsibility of both the employer and employees. Wearing protective clothing and using safety equipment correctly helps keep workers safe. Your employer will emphasize the safety practices that employees must follow in your workplace. The government agency that promotes safety in the workplace is the Occupational Safety and Health Administration (OSHA). You will be req uired to follow the specific OSHA regulations that apply to your workplace.

Copyright Goodheart-Willcox Co Inc

Chapter 3 Shop Safety

35

3.5 Safety Data Sheets Safety data sheets (SDS), formerly called material safety data sheets (MSDS), provide information about the various chemicals, chemical compounds, and mixtures that are used in an industrial setting. A typical SDS has a leading paragraph identifying the manufacturer and describing the proper use

of t he information in the SDS. The sheet also contains 16 sections, as described in the table in Figure 3-14. SDSs must be kept in a general location that is easily accessible by employees a nd by emergency response personnel in the event of an emergency. Some companies subscribe to an online service that makes SDS information immediately available on tablets and other mobile devices, Figure 3-15.

Required Sections in a Safety Data Sheet Section

Description

Section 1. Identification

Provides a unique product identifier, as well as the contact information for the manufacturer, recommended uses, and any restrictions on the use of the chemical.

Section 2. Hazard(s) identification

Describes hazards associated with the chemical and required label elements.

Section 3. Composition/information on ingredients

Specifies chemical ingredients and trade secret claims.

Section 4. First-aid measures

Describes both acute (immediate) and delayed symptoms and effects, as well as required treatment.

Section 5. Fire-fighting measures

Describes chemical hazards from fire and lists appropriate equipment and techniques for extinguishing the fire.

Section 6. Accidental release measures

Explains proper measures for clean-up and containment of an accidental spill or release of the chemical. Also specifies emergency procedures and protective equipment needed.

Section 7. Handling and storage

Describes precautions for safe handling and storage, as well as incompatibilities.

Section 8. Exposure and controls/personal protection

Specifies exposure limits, including OSH.A:s Permissible Exposure Limits (PELs), ACGIH Threshold Limit Values (TLVs), and any other exposure limits recommended by the manufacturer, importer, or employer. Also includes recommended engineering controls and personal protective equipment (PPE).

Section 9. Physical and chemical properties

Specifies the physical and chemical characteristics of the chemical.

Section 10. Stability and reactivity

Lists the stability of the chemical and the possibilities for hazardous reactions with other substances.

Section 11. Toxicological information

Describes the toxicity of the chemical, including routes of exposure, symptoms of toxicity, acute and chronic effects of toxicity, and numerical measures of toxicity.

Section 12. Ecological information

Lists potential ecological effects of the chemical.

Section 13. Disposal considerations

Explains how to dispose of the chemical safely.

Section 14. Transport information

Describes transportation requirements and safety precautions for transport.

Section 15. Regulatory information

Lists regulations pertaining to the chemical.

Section 16. Other information

Lists the date the SDS was written or last revised. Goodheart·WIIIcox Pvbltsher

Figure 3-14. Required sections for a safety data sheet.

Ccpynght Goodheart·WIIIcox Co .• Inc.

Machining Fundamentals

36

SAFETY DATA SHEET Section 1: Product and Company Identification Product Name:

Solvent Based Anti-Spatter (Aerosol)

Product Identifier: Product Use: Item Code(s): SDS Code:

Anti-Spatter Prevents Spatter Build Up in Welding Operations BDAS-S-160ZC 5001

Manufacturer: Physical Address:

Welding Material Sales 1340 Reed Road Geneva, IL 60134 Business Phone: 630-232-6421 Business Fax: 888-733-1512 E-mail Address: [email protected] Emergency Phone: 800-424-9300 Date of Preparation: May 10, 2015 OSHA Regulatory Status: D1B, D2A,D2B,A WHMIS Classification:

Section 2: Hazards Identification CLASSIFICATION OF THE SUBSTANCE OR MIXTURE: CLP/GHS Classification (1 272/2008): Physical

Health

Environmental

None

Eye Irritation Category 2A Skin Irritation Category 2 Specific Target Organ Toxicity- Single

None

Exposure Category 3 (H335, H336) Carcinogen Category 2 EU CLASSIFICATION (67/548/EEC)· Xn R40 (Carcinogen Category 2) Label Elements WARNING! Contains methylene chloride

~~

Hazard Phrases H315

Causes skin irritation.

H319 H335 H336 H351

Causes serious eve irritation. May cause respiratory irritation. May cause drowsiness or dizziness. Suspected of causing cancer.

Revised May 10, 2015

Solvent Based Antl·Spntter Aerosol SDS

Page 1 ol6

Goodheart·W/1/cox Publisher

Figure 3-15. Safety data sheet information for every chem ical in use at a facil ity must be made easily available to all employees. Copynghl Goodheart-WII cox Co Inc

Chapter Review Summary • Shop safety should be maintained throughout your machining career, not just in the training program, to help prevent injuries. • Wear proper clothing that will not be caught in the machine. • Use the appropriate safety equipment when working with machines to protect yourself from injury.

4. Why should oily rags be placed in a safety container? 5. When working in an area contaminated with dust or solvent fumes, wear a dust mask and be sure that there is adequate ___. 6. Safety glasses should be worn _ _ . A. most of the time B. only when working on machines C. the entire time you are in the shop D. None of the above.

• Awareness barriers and machine shields are put in place to protect machine users.

7. Why is it necessary to take special precautions when handling long sections of metal stock?

• Get proper instruction before operating any machine. • Warning signs are placed around a shop to identify potential hazards.

8. Why is it important to ask for help when moving heavy machine accessories or large pieces of stock?

• Fires are classified into four different categories (A, B, C, and D) according to the type of material that is burning. • Safety data sheets (SDS) are required for every chemical present in the machine shop and provide information about the chemical, including emergency information.

Review Questions Answer the following questions using the information provided in this chapter. 1. Why is shop safety so important? 2. Most shop accidents are caused by ___ or by not observing ___. 3. Why should compressed air not be used to clean chips from mach ine tools?

9. What should you do before operating a machine tool if you are taking medication of any sort? 10. What is the purpose of a machine shield? 11. Use a(n) ___, not your hand, to remove chips and shavings. 12. Secure prompt ___ for any cut, bruise, scratch, or burn. 13. Always stop machine tools before making _ __ or taking measurements. 14. Why should tools be kept properly sharpened and maintained? 15. What type of fire extinguisher should be used to put out an electrical fire? 16. Briefly describe the information available on a safety data sheet.

CHAPTER

4

Understanding Drawings Chapter Outline 4.1 Dimensions 4.1 .1 US Conventional and Metric Dimensioning 4.1.2 Dual Dimensioning 4.1 .3 Coordinate Dimensioning 4.2 Information Included on Drawings 4.2.1 Materials

Learning Objectives 4.2.2 Surface Fi nishes 4.2.3 Tolerances 4.2.4 Other Information 4.3 Prints 4.4 Types of Drawings Used in the Shop 4.5 Parts List 4.6 Drawing Sizes

After studying this chapter, you will be able to: • Read drawings that are dimensioned in fractiona l inches, decimal inches, and metric units. • Explain how and why coordinate dimensioning is used. • List the information found on a typical drawing. • Explain how prints are generated. • Describe how detail, subassembly, and assembly drawings differ. • Explain the purpose of a parts list or bill of materials. • Recall standard drawing sheet sizes.

Technical Terms American Nationa l Standards Institute (ANSI) bilateral tolerance bill of materials dimensions dual dimensioning International System of Units (SI) limit dimensions microinch

micromete r (micron) parts list profilometer scale d rawing SI Metric system tolerance u nilateral tolerance US Conventional system working drawing X-Y coordinate system

Chapter 4 Understanding Drawings

39

M

any products manufactured today are an assembly of parts supplied by a number of different industries located all over the world. It would not be possible for industry to manufacture a complex product like the passenger plane in Figure 4 -1 without using drawings. Drawings show the machinist what to make and identify the standards that must be followed so the various parts will fit together properly. The resulting parts will also be interchangeable with similar components on equipment already in service.

Drawings range from simple freehand sketches, Figure 4-2, to detailed drawings for complex products, Figure 4-3. Lines of different types and thicknesses are used to give drawings meaning, Figure 4-4. This "Alphabet of Lines," devised by the Americau Natioual Staudards Institute (ANSI), is standardized so that each type of line has the same meaning wherever drawings are made a nd used. • Visible lines are used to draw the edges of objects and features that can be seen in each view. Visible lines are drawn with a thick lineweight so the part features are easily visible after other linetypes are added.

lr;~

l sr

r-x-· ~~~fl ~~~:m8 \{11.75, 2 HOLES SPACER

IM_photoiShutterstock.com

Figure 4-1. Thousands of drawings were required in the design and construction of aircraft like this passenger aircraft. Standards and specifications had to be exact because the components were manufactured in several geographic locations.

MATERIAL- STEEL AISI IOZO Gcodhe