An electrical connector (1) of the present invention includes an insulative base (10) defining a plurality of passageways (101) to receive a plurality of conductive terminals (19) therein, a base plate (142) retained in the insulative base, a cover (12) movably assembled on the base, a cover plate (142) retained in the cover and a cylindrical actuator (16). The base defines a through hole (1021) thereof. The base plate defines a through hole (1421) and a guiding slot (1422). The cover defines a plurality of passages (124) corresponding to the passageways of the insulative base and a through hole (123). The cover plate defines a through hole (1411) and a guiding portion (1413) sliding in the guiding slot. The cylindrical actuator is received and rotating in said through holes. At least one inner edge of the through hole of the base plate extends outwards to form an edge portion with a smooth surface thereon.