· ---------,

LateralspreadisoftenexpressedinrelativetermsbythewidthspreadcoefficientSwwhichisequal tothefollowing:

(13-3)

workpiecethicknessbeforeandafterthicknessreduction,respectively.

13.2HillandMcCrumFormulaforSpread

TheformulaforwidthspreadderivedtheoreticallybyHill[2]canbegiveninthefollowinggeneralform:

Sw=0.5exp[-0.707ci](13-4) where

c=constant

LJRt:.=rollcontactlengthinthicknessreduction Rworkrollradiususedinthicknessreduction t::,thicknessdraft.