The maximum normal stress in $\mathrm{MN} / \mathrm{m}^{2}$ for the thin walled beam of square cross section of outer dimension $120 \mathrm{~mm} \times 120 \mathrm{~mm}$ and wall thickness $1 \mathrm{~mm}$ under the action of moment $\mathrm{M}_{0}=96 \mathrm{Nm}$ as shown in the figure is__________________ (in three decimal places).
The maximum normal stress in $\mathrm{MN} / \mathrm{m}^{2}$ for the thin walled beam of square cross section of outer dimension $120 \mathrm{~mm} \times 120 \mathrm{~mm}$ and wall thickness $1 \mathrm{~mm}$ under the action of moment $\mathrm{M}_{0}=96 \mathrm{Nm}$ as shown in the figure is__________________ (in three decimal places).