from GIOV You must correct the reference to the Inertia and the Section Modulus. The result should be with the x-axis as the base I x-x and Sx-x.
Sx-x=Wx-x=Zx-x=I x-x/ Ymax
Ix-x= Inertia momentum from the centroid x-x axis
Ymaz= Distance from the centroid x-x axis to the most extreme fibre.
<https://en.wikipedia.org/wiki/Section_modulus#Elastic_section_modulus>
https://en.wikipedia.org/wiki/Section_modulus#Elastic_section_modulus
