Abstract: The reasonable quantity matching and determination is given for the technological parameters——tool width ratio (w/h), blank width ratio (b,/h) and relative reduction [η＝(h0-h)/h0] of the new stretching theory. This provinces a basis which can be abided by for working out forging technology and an important criterion for building the expert system of heavy forgings.

Key words: Blank width ratio, Reasonable matching, Relative reduction, Tool width ratio