the strength of magnetic field (= an area around something magnetic) that is required to reduce the magnetization of a magnetized material to zero after it has been made as magnetic as possible

Once the coating is applied, it is checked for thickness, durability, and coercivity. 涂层涂好后，要对其厚度、耐久性和矫顽力进行检查。

Making a core from thin iron sheets, interleaved with an insulating material, brings the coercivity of the core down without harming its useful properties.