Abstract: A control mechanism for a chair having two components which are pivotally movable relative to each other wherein one of the components is the chair seat. The other chair component, in one form of chair such as an office chair, is the seat back. In another form of chair, such as a swivel rocker, the other component is the chair base. The control mechanism includes a torsion bar which has a main body portion that extends front to rear of the seat member, and end portions, one of which is attached to the seat member and the other one of which is attached to the other chair component. During relative pivotal movement of the two pivotally connected chair components, the torsion bar acts as a spring to yieldably resist the pivotal movement and return the chair components to their original positions when the load is removed.