Excerpt from Gage Design and Gage-Making: A Treatise on the Development of Gaging Systems for Interchangeable Manufacture, the Design of Different Types of Gages and Their Production, Including Precision Machining Operations, Lapping, and Various Modern Appliances for Gage Measurement The cost of manufacturing any mechanism may be greatly affected, first, by the tolerances specified, and, second, by the gages used to insure that these tolerances are adhered to. There has been, and still is, a great deal of misunderstanding with regard to tolerances and their application in shop work. Briefly stated, tolerances should be based upon the working requirements of the mechanism to be made, and should be as large as possible, consistent with the purpose of the part or combination of parts to be made. Unnecessary accuracy which does not improve the product merely increases the manufacturing cost, and, hence, is sheer waste. After the tolerances have been established, the means for insuring that the desired tolerances are adhered to in the machining operations must be considered. The gages to be used must be so designed and made that they are not only accurate, but practicable, and adapted to shop use. The relation between the gaging system and the design of jigs and fixtures is also essential. This book deals with such fundamental and vital points as have been outlined above, and is, therefore, regarded as a valuable addition to the technical literature of the day. Much has been published on manufacturing practice, but comparatively little on the design and making of gages; yet, gages control the different manufacturing processes and insure that the required degree of interchangeability is obtained. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

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MACHINERYS REFERENCE SERIES. NUMBER 64- GAGE MAKING AND LAPPING. In the following pages of this book are compiled a number of articles relating to gage making and lapping. These articles have been contributed from time to time to Machinery by various writers. In some cases the opinions expressed differ slightly as to the best practice, each writer describing the methods with which he personally has had most experience or best success. CONTENTS Principles of Gage Making, by F. E. SHAILOR. The Manufacture of Gages. Lapping Flat Work and Gages, by F. E. SHAILOR. The Rotary Lap, by A. J. DELILLE. MiscelIaneous Laps and Lapping Operations. Originally published in 1910. Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce and increasingly expensive. We are republishing these classic works in affordable, high quality, modern editions, using the original text and artwork.

This handbook is a both a description of the current practice at the National Institute of Standards and Technology, and a compilation of the theory and lore of gauge block calibration. Most of the chapters are nearly self-contained so that the interested reader can, for example, get information on the cleaning and handling of gauge blocks without having to read the chapters on measurement schemes or process control, etc. This partitioning of the material has led to some unavoidable repetition of material between chapters. The basic structure of the handbook is from the theoretical to the practical. Chapter 1: basic concepts and definitions of length and units; Chapter 2: history of gauge blocks, appropriate definitions and a discussion of pertinent national and international standards; Chapter 3: physical characteristics of gauge blocks, including thermal, mechanical and optical properties; Chapter 4: a description of statistical process control (SPC) and measurement assurance (MA) concepts; and Chapters 5 and 6: details of the mechanical comparisons and interferometric techniques used for gauge block calibrations. Full discussions of the related uncertainties and corrections are included. Finally, the appendices cover in more detail some important topics in metrology and gauge block calibration.