PREFACE 



Many engineering departments, perhaps most, compile and keep up to date a 

 manual which may be called the standards book, reference book, engineering depart- 

 ment standards, or which may be given some other name. Also, many design 

 engineers build their own book or manual. In such books will be found a vast fund 

 of engineering data and many methods of design procedure not found in existing 

 handbooks. 



When Product Engineering was launched as a pubhcation to serve the design 

 engineers, it was obvious to the editors that a great service could be rendered to the 

 profession by gathering and publishing data, information, and design procedures such 

 as are contained in engineering department manuals. Thus, the first number of 

 Product Engineering in January, 1930, contained a reference-book sheet for design 

 calculations, a feature which has been continued in practically every number. Soon 

 afterward, there was added to Product Engineering's editorial content another regular 

 feature, a two-page spread illustrating standard constructions, possible variations by 

 which to achieve a desired result, and similar design standards covering constructions, 

 drives, and controls. 



It was soon found impossible to meet all the requests for additional copies of 

 reference-book sheets and design standards. The demand continued to increase and 

 numerous readers suggested that the material be compiled into book form and pub- 

 lished. It was in answer to this demand that the authors compiled this book. 



Other than the major portion of the chapter on materials and a few other pages 

 that have been added to round out the treatment of certain subjects, all the material 

 in this book appeared in past numbers of Product Engineering, although some of it has 

 been condensed or re-edited. Very little of the material in this book can be found in 

 the conventional handbooks, for this Handbook of Mechanical Design contains practi- 

 cally no explanations of theoretical design. It confines itself to practical design 

 methods and procedures that have been in use in engineering design departments. 



The authors wiU welcome suggestions from users of this book and especially 

 desire to be notified of any errors. 



We wish to make special acknowledgment of the material on typical designs 

 appearing in Chapters IV and VI, by Fred Firnhaber, now of Landis Tool Company; 

 the nomograms by Carl P. Nachod, vice-president of the Nachod & U. S. Signal Co.; 

 the standard procedure in the design of springs by W. M. Griffith of Atlas Imperial 

 Diesel Engine Company; the spring charts by F. Franz; the methods for calculating 

 belt drives and other nomograms by Emory N. Kemler, now associate professor of 

 mechanical engineering at Purdue University; the nomograms for engineering calcu- 

 lations by M. G. Van Voorhis, now on the editorial staff of Product Engineering; and 

 to S. A. Kilpatrick and 0. J. Schaefer for their brilliant series of articles, which have 



