1.The iron core of the AC contactor is made of Silicon steel sheet with double E shape；The iron core of the DC contactor is made of soft iron with U shape. 

2. The AC contactor uses grid plate arc-chute. The DC contactor uses magnetic blowout device. 

3.Since the AC electricity goes through the coil, in order to eliminate the vibration and noise on the iron core,we put the short-circuit ring on the iron core. But DC contactor doesn’t need it. 

4.The number of windings and resistance of the AC coil are less than the DC contactor. 

5.The start-up current of the AC contactor is high, it’s not suitable for the frequently start-off equipment, the frequency is up to 600 per hour, but the frequency of the DC contactor can be up to 2000 per hour. 

6. The AC contactor is suitable for breaking AC electricity, the DC contactor is for breaking DC electricity. 

7. The cost of the AC contacot is lower than the DC contactor  - See more at: http://..........com/pid18073949/Ac-Contactors-Magnetic-Contactors-Series-Gmc-85-Contactor.htm