Now if your Ans is yes then I have one more  question to ask. .ie don't u agree that we should not say stress as a tensor of 2nd order rather only tangential stress as tensor of 2nd order and normal stress as tensor of 0 order or scalar .
The stress tensor can be written as: $$\sigma_{ij}=-p \delta_{ij}+\sigma'_{ij}\label{1}\tag{1}$$ where $\sigma_{ij}'$ is called the extra stress tensor.   From what I understand pressure is pressure is force per unit area, so that the force acting on the surface $d\vec A$ is given by:  $$\vec F=-p d\vec A\label{2}\tag{2}$$ (This has the effect that the force on an infinitesimally thin surface due to a continuous pressure is zero). However, $\sigma_{ij}$ represent the force in the $i$ direction on a surface with normal in the $\hat e_j$ direction. So the force acting on a surface $d \vec A$ must be: $$F_i=\sigma_{ij}dA_j\label{3}\tag{3}$$ Equations (2) and (3) clearly do not agree (even if we look soley at the force in the $d\vec A$ direction they don't agree). So my question is what is the exact meaning of pressure in expression (1) and why do we not have: $$\sigma_{ii}=-p$$
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