The cutting force (Fz) acts in the direction of cutting. In lathes, this is tangential to the workpiece diameter at the cutting point, i.e. vertical. Due to heavy chip friction in metal-cutting, the horizontal force (Fy) can be as high as 76% of the cutting force (Fz). As these forces are in equilibrium, forces on the slideway faces and edges, can be found by solving equations S Y = 0, S X = 0, SZ=0,andSMx =0.Thesolutionsare:
Force on guideway edge face D = Fy = D
ForceonguidewayfaceC=FzYf Fyh+G=C