Abstract: An apparatus for constructing an interlocked grid system which may be suspended from the main structure of a building for use as a ceiling panel support is disclosed in which transverse members interlock with suspendable support members. A tongue on each end of opposing transverse members communicates with a rectangular hole in the support member. The upper and lower edge of each tongue is deflected to form upper and lower shoulders which face backward toward the transverse member. Upon insertion of the tongue into the rectangular hole, the shoulders engage the support member at the upper and lower ends of the rectangular hole. The leading end of the tongue is wedged and maintained in position within the orifice by a centrally located reinforcement bead on the opposing transverse member. The reinforcement bead extends across the junction of the tongue with the transverse member to perform a reinforcing function as well as the wedging function.