A twist-locking fitting for securing a strut to a rod includes first and second fitting pieces. Each fitting piece includes a half-nut portion having an interior surface defining an axis extending through first and second axial ends of the half-nut portion. Each fitting piece includes an outer flange extending outward from adjacent the first axial end of the half-nut portion and an inner flange extending outward from adjacent the second axial end of the half-nut portion. The inner flange is spaced axially apart from the outer flange to define a clearance gap. The fitting pieces are positionable on the strut in an unsecured position in which the fitting pieces are movable relative to one another. The fitting pieces are rotatable relative to the strut to move from the unsecured position to a secured position, in which the fitting pieces are fixed relative to one another on the strut.