# force on a piece of magnetized material

Suppose that we have a magnetized piece of material that we put into a non-uniform external magnetic fiel $$\vec{B_e}$$, which is stationary. Is it true that the force on this piece a material is :

$$\vec{F}=(\vec{M}\cdot \vec{\text{grad}})\vec{B_e}$$

where $$\vec{M}$$ is the magnetization vector.