Abstract: A tilt control apparatus is provided for use on a chair having a base and a backrest, and includes a center retainer from which a pair of torsion bar segments protrude. A tubular outer casing is received over each torsion bar segment and is affixed to the center retainer, and an end bar retainer is received on the distal end of each torsion bar segment for rotation therewith. A structure is provided for restricting axial and rotational movement of the end retainers relative to the outer casings, holding the end retainers in place on the apparatus and permitting the torsion bar segments to be pre-torqued, if desired.