Abstract: A border support spring has a pair of complementary torsion wires for providing increased resilient border support to a mattress spring assembly. Each torsion wire of the present invention is bent to have an elongated center section having a pair of spaced ends from which extend divergently projecting transverse arms. Each transverse arm terminates in an end portion which is adapted to be secured to the top or bottom border wire of the mattress spring assembly. The end portions and center sections are each generally orthogonal to the orientation of the transverse arms. The center sections of the pair of torsion wires journal together to prevent relative translational movement, but permit pivotal relative movement between the transverse arms. A helical laced wire is used to journal the center sections of the torsion wires together and extends substantially the entire length of the center sections.