The connector has: an electric-communication connecting base with an end piece which is formed on the front face thereof an annular member with an outer peripheral thread, the pins having piercing ends exposed each for a set length from the annular member and a reduced annular portion on the front end of the annular member; a conductor extending-through seat made of insulation material having an opening outer and an inner ring extending from the end face of the seat to the annular member, so that an annular groove formed by the outer and inner rings being able to slip over the reduced annular portion, conductors being bent and positioned on the outer and inner rings; and a rotation control member having an inner thread on its inner side facing to the thread on the annular member to screw connect with the conductor extending-through seat having the conductors positioned to axially press and thrust the conductors for piercing and connecting.