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Preface -

The impact or cold extrusion of metals is a " chipless machining"

process that can greatly reduce costs of material and labor

if properly applied. Within certain limitations in shape, some

parts can be produced by this process that often require only

trimming to length. On others, the secondary operations are

reduced greatly over those required for several of the competing

processes. Finally, certain components can be made that can be

produced by no other method.

Impact extrusion can be employed for the production of parts

from a wide range of metallic materials. In commercial production

at present are components produced from aluminum,

copper, lead, magnesium, tin, zinc and their alloys and various

steels. In the development stage are parts produced from less

common metals, such as titanium and molybdenum.

The aim of this book is to present a coordinated description of

impact extrusion. Its purpose is to present the information required

by an engineer to determine whether the process is

applicable to his products, and to assist the metallurgist in

selecting the metal to be used.

The book is based on personal experience, talks, and correspondence

with producers of components, and a search of the

free-world technical literature. It is divided into two parts.

The first deals with the underlying principles and the characteristics

of the process; the second, with the metals being extruded

and the products.

It is a pleasure to express my thanks to all those that assisted

in developing the theme. I feel particularly indebted to T. J.

Dolan, who prepared a number of the sketches; to my son,

Larry, who assisted in the preparation of the manuscript; and

to my wife, Helen, who prepared the graphs and many of the

sketches, and assisted in proofreading.

Westfield, New Jersey

January, 1964

John L. Everhart