correction factor KS tot
σFP / σF lim = (YST YNT Yδ YR YX ) / SF
YST stress correction factor, relative with refference gears
YNT life factor for tooth-root stress for reference test cond.
Yδ notch sensitivity factor relative to polished test piece.
YR relative roughness factor.
YX size factor
SF factor for savety from tooth breakage
σFP / σF lim = (YST YNT Yδ YR YX ) / SF  
 enter new value in the main program window manually !  
σF lim = nominal tooth-root stress reference gears (fatique).
σFP = permissable tooth-root stress actual gears.