Abstract: A sort of forging method is proposed, which can control there exists neither axial tension stress nor crosswise tension stress in the centre of the deformation zone of blank, which requires that a flat platen is used over and a big platform below. The method is called new FM forging method. In the paper, the quantity relation between the spreading ratio [ψ＝（b－b0）/b0 ] and the relative reduction (n =Δh/h0) is given. According to the given data table, the section varying calculation during the blank being compressed by the new FM method can be done and the best matching among tool width ratio (ω/h). Blank width ratio ( b / h ) and relative reduction can be achieved.

Key words: Blank width ratio, Forging, New FM