Socket

A socket adapted for mounting an electrical part for use in a burn-in test of said electrical part, said electrical part of a generally parallelepiped configuration having mutually facing top and bottom surfaces and two sets of mutually facing side surfaces with contact lead members provided on only one side of one set of the two sets of mutually facing side surfaces, comprising a base member, resilient contact element means secured in said base member adapted to make contact with the lead members of said electrical part, a reciprocating cover means capable of reciprocating motion in respect to said base member, said reciprocating cover means having a cam means adapted to be in contact with said contact element means such that as said reciprocating cover means moves from a first position to a second position for mounting said electrical part said cam means causes said contact element means also to move from a first original position to a second electrical part mounting position, and upon said reciprocal cover means returning to said original position and contact element means also moving back to said original position from said second position thereby providing electrical contacting between said lead members and said contact element means and means formed within said base member for precisely guiding and positioning said electrical part during mounting of said electrical part in said socket and for holding said electrical part after mounting to ensure reliable contacting, said guiding, positioning and holding means including wall members in the base member for controlling the movement of at least two mutually facing surfaces of the electrical part, blind holes in the base member for receiving protrusions extending from the electrical part on the same side surface as the lead members, and mounting surface means in the base member for receiving said lead members.