Quality control points of AC contactor iron core

Why the iron core of AC contactor vibrates?
AnBen Electric Co., Ltd. is a professional iron core manufacturer of AC contactor. We are specialized in producing CJX2 iron core, cjx1 iron core, cj20 iron core and cj12 iron core. As for the problem of iron core vibration, the big factor is the uneven plane of AC contactor iron core.