Abstract: A missile has fins that rotate about a single axis to deploy from a stowed position to a deployed position. A foil longitudinal axis of each fin is angled relative to a shaft of the fin, such that a single-axis rotation of the shaft moves the foil from the stowed position to a deployed position. A coil spring may provide both torsion and compression forces to rotate the fin into the deployed position and lock it into place. Torsion rotates the shaft until it reaches a seat on a bushing that is around the shaft. Then compression forces from the spring engage a keyed protrusion on the shaft with a corresponding keyway in the bushing, locking the shaft in place. There may be an additional lock once the fin is deployed, such as a spring-loaded pin in the missile body that engages a depression in the shaft.