Tool and Die Materials

PREFACE A very large variety of sheet-metal forming processes is used in modern sheet-metal press-working shop practice. Many of these deformation processes, used in making aircraft, automobiles, and other products, use complex equipment that is derived from the latest discoveries in science and technology. With the ever- increasing knowledge of science and technology, deformation processes promise to be even more complex to satisfy the demand for more productivity, lower cost, and greater precision. However, for all their advantages, the more sophisticated deformation processes of today have not replaced the need for basic sheet-metal forming processes and dies. This book draws on the author’s 30-plus years of experience as an engineer and provides a com- plete guide to modern sheet-metal forming processes and die design - still the most commonly used manufacturing methodology for the mass production of complex, high-precision parts. Much more prac- tical than theoretical, the book covers the and “whys” of product analysis, and the mechanisms of blanking, punching, bending, deep drawing, stretching, material economy, strip design, movement of metal during stamping, and tooling design. Readers will find numerous illustrations, tables, and charts to aid in die design and manufacturing processes; Formulas and calculations needed for vari- ous die operations and performance evaluation are included; and designations, characteristics, and typ- ical applications of various carbon and alloy steels for different die components are evaluated. The book concentrates on simple, practical engineering methods rather than complex numerical tech- niques to provide the practicing engineer, student, technician, and die maker with usable approaches to sheet-metal forming processes and die design. The first part of the book deals with the structures of metals and the fundamental aspects of the mechanical behavior of metals. Knowledge of structures is necessary to controlling and predicting the behavior and performance of metals in sheet-metal forming processes. The second part of the book covers all aspects of forming sheet metal. It presents the fundamental sheet-metal forming operations of shearing, blanking and punching, bending, stretching, and deep draw- ing. Mechanics of various drawing processes indicate ways in which the deformation, loads, and process limits can be calculated for press forming and deep drawing operations. The book includes various draw- ing processes nosing, expanding, dimpling, spinning and flexible die forming mostly used in the aircraft and aerospace industry. Dies are very important to the overall mass production picture, so they are discussed in the last sec- tion of the book, which presents a complete picture of the knowledge and skills needs for the effective design of dies for sheet-metal forming processes described. Special attention is given to: Formulas and calculations needed for various die parts. Rules of thumb and innovative approaches to the subject. Properties and typical applications of selected tool and die materials for various die parts. ...