Abstract: A tester for backplanes, printed wiring boards and like electrical assemblies has contacts that mate without interference with contacts of the assembly under test, and has a displacement mechanism that shifts the assembly laterally. The lateral displacement brings the mated contacts into interfering engagement with each other for effecting electrical connection between them.

Abstract: Electrical socket apparatus for integrated circuit packages and like devices has a contact for receiving the male connection element of the circuit device through an aperture in a folded spring section and for seating the male element at the mouth of the folded section. The shank of the contact is split, which forms two branches that provide a resiliently-acting interference fit of the shank within a contact-mounting aperture. A heat sink, preferably employed in a socket with the contact and nested within the profile of the contact spring section, has a heat receiving panel for abutting against the underside of the mounted circuit device.