The plastic forming of metals is a branch of technology, in which great
progress has been achieved mainly by collecting practical data resulting
from long-time experience. The contribution of theoretical analysis to
this progress is not significant. The common argument was, that such an
analysis is too difficult and often even impossible. However, the
constantly increasing significance of coldwork processing in industrial
practice and the progress in the automatic control of these processes,
demanding a broad knowledge of the influence of various parameters, and
also the need to improve the mechanical behaviour of coldworked elements
have proved beyond doubt that better understanding of the theory of
plastic forming processes is necessary. This general trend has become
evident in several recent publications in recent years, even though
these represent only the engineering, approximate approach to
theoretical analysis. Recent significant progress in the mathematical
theory of plasticity allows to build an analysis of plastic forming
processes on a more sound basis. In particular there have been developed
graphical methods by means of which slip-line and hodograph meshes are
constructed for plane strain and axially symmetric problems. These
graphical methods yield not only the required forces but also the. mode
of plastic deformation, even for very complex problems. Numerical
procedures also give good results if the digital computer technique is
employed.