Contact Stress Sphere in Contact Flat Surface Equation
The following equation will determine the contact stress between a sphere and a flat surface with known young's modulus and applied load.
E = Young’s modulus
F = load
r1, r2 =radii
v = Poisson’s ratio
Contact stresses two sphere's in contact same material and differnet spherical radius.
Contact area radius
Mechanical Engineers Data Hanbook, James Carvill 1993 Page 51