The explicit formula for the components ( $T^{i j}$ ) of the magnetic Maxwell Stress Tensor in terms of the magnetic field components $B_i, B_j$, and the Kronecker delta $\delta_{i j}$ is:
$$ T^{i j}=\frac{1}{\mu_0}\left(B_i B_j-\frac{1}{2} \delta_{i j} B^2\right) $$
The Maxwell Stress Tensor describes the stresses and pressures that the electromagnetic field exerts on a boundary surface, essentially defining the flow of momentum due to the field.