a hinge unit useful in the manufacture of readily assembled and erect shelving and storage units and furniture comprises an elongate locking member having a first portion adapted to be received within a slotted channel in the surface of a first panel , a second portion extending away from the elongate member for attaching the hinge to a second panel and integral axial flexion member between the two portions of the hinge . the cross - sectional shape of the elongate locking member and the channel are selected to prevent rotation of the locking member within the channel .