Workshop technology Part I An introductory course Workshop technology Part I An introductory course SI UNITS Dr. W. A. J. CHAPMAN MSc (Eng), FIMechE, HonFIProdE I~ ~?io~~~:n~~:up LONDON AND NEW YORK First published by Butterworth-Heinemann This edition published 2011 by Routledge 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN 711 Third Avenue, New York, NY 10017, USA Routledge is an imprint of the Taylor & Francis Group, an informa business First published in Great Britain 1943 Second edition 1955 Third edition 1959 Fourth edition 1962 Fifth edition 1972 Copyright © 1972, W A J Chapman. All rights reserved The right of WA J Chapman to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England WIT 4LP. Applications for the copyright holder's written permission to reproduce any part of this publication should be addressed to the publisher British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress ISBN 978-0-415-50302-0 Preface to first edition The scheme of the present work was in my mind, and partly on paper, before the present catastrophe overtook us, and, with many other works of peaceful construction, was shelved. The trend of events, however, indicate that its publication should be of value to the war effort, so that I have persevered in completing this first portion. My chief regret is that I was not qualified to write it fifteen years ago. At that time the status of our artisan workers was being allowed to fall relative to other members of the community. The artisan professions were neglected by educationalists, by writers and by public thought, a state of affairs which led to a dearth of suitably qualified prospective workers. What this policy has cost us cannot be assessed, but it is now obvious that it almost brought us to disaster. That the artisan is worthy of a reasonable social position can be testified by those who have lived and worked with him. That the work he does calls for high skill and training should be evident from jobs such/ as that of turning the pair of rolls shown at Figs 39 and 41, an operation demanding a level of performance comparable with that in many so-called professions. I have written for the men who do such work and for those who aspire to it. It is difficult to compromise between academic theory and everyday practice, but it is hoped that the fundamental principles underlying work- shop processes have been clearly explained and that the reader will be able to understand more easily the processes described and to perform them in the workshop. The work covered in this volume is approximately that of the first two years of a senior part-time course in Technical Colleges and includes most of the material necessary for the City and Guilds Inter- mediate Examination in Machine Shop Engineering. It should also be use- ful to students for the preliminary work in Workshop Technology leading to the Higher National Certificate in Production Engineering. In the preparation of the diagrams a great deal of help has been given by the kindness of various firms and institutions. Their names are appended to the illustrations concerned and I should like to offer them my sincere thanks. Finally, I feel that the Publishers in producing this book at such a price, and amid such difficulties, have performed a task worthy of commendation. W.A.J.C. Oakengates 1943 Preface to the fifth edition The fifth edition of this book marks somewhat of a landmark in its career. To keep abreast of modem developments it is 'going metric' and this new edition has been revised to conform with the SI metric system of units and conventions. The Fourth edition, in British imperial units, will still be available for use in those countries where the SI system has not yet been adopted. A further noteworthy aspect in the career of Workshop Technology is that, since it was first published in 1943, its circulation has exceeded -! million copies and it has found friends in all parts of the world. The need to preserve high standards of quality in the workshop and a dedicated approach on the part of technicians and craftsmen is just as important now as it was at the time of the first publication. So, also, is the need to provide suitable and reliable information for those outside the workshop who seek the help of the book. I have amended the text, where necessary, to cover developments in practice and equipment, and, on this account, I should like to record my appreciation to the firms and individuals who have given generous help and advice. The Publishers, as always, have produced a good job and I hope that the book will continue to further the aims I entertained when I originally produced it. W.A.J.C. Hatfield 1971 Contents 1 Introduction - materials - iron and steel Introduction - Materials - Pure iron - Blast furnace - Pig iron - Cast iron -Alloy cast irons - Cupola - Wrought iron - Puddling process - Malleable cast iron - Steel - Open hearth - Bessemer - Carbon steel - Crucible and electric processes 1 2 The properties and treatment of iron and steel Brittleness - Ductility - Elasticity - Hardness - Malleability - Plasticity - Toughness - Microstructure of steel - Effect of heating steel - Critical range - Heat treatment of steel - Furnaces and furnace temperatures - Pyrometers - Reasons for heat treatment - Annealing - Normalising - Hardening and tempering - Hot and cold working - Case-hardening - Workshop tests for iron and steel 31 3 Non-ferrous metals and alloys - Alloy steels - Preparation of metals Aluminium and its alloys - Copper and its alloys - Lead - Tin and alloys - Bearing metals - Bronze - Zinc - Brass - Alloy steels - High speed steel - Alloy tool steels - Cutting carbides - 'Rare' metals - Ceramic tools - Hot rolling - Cold rolling - Cold drawing - Moulding and casting 59 4 Heat processes - forging, riveting, soldering and brazing Hand forging -The forge and tools - Upsetting - Drawing down - Bending - Punching - Drifting - Welding - Forging examples - Power hammers and their tools - Drop forging - Drop' stamps and dies - Riveting - Soldering - Brazing - Silver soldering - Adhesive bonding 91