The pseudo-rigid-body model concept allows compliant mechanisms to be analyzed using well-known rigid-body kinematics. This paper presents a pseudo-rigid-body model for initially circular functionally binary pinned-pinned segments that undergo large, nonlinear deflections. The model approximates the functionally binary pinned-pinned segment as three rigid members joined by pin joints. Torsional springs placed at the joints model the segment’s stiffness. This model has been tested by fabricating several such segments from a variety of different materials. An example mechanism incorporating functionally binary pinned-pinned segments is also presented.