a bus seat comprising an aisle support having a first hexagonally shaped aperture or cavity and a window side support having a second hexagonally shaped aperture or cavity . a seat is hinged to the aisle support and the window support . a seat back is employed which has hexagonally shaped apertures or cavities which each interengage hexagonal shaped torsion members which in turn interengage the cavities in the aisle and window supports . the first and second hexagonally shaped torsion members in combination with the apertures inhibit rotation of the seat back with respect to the aisle and the window side supports and absorb energy when the seat back is rotated relative to the aisle and window supports . the hexagonally shaped cavities are manufactured without significant knit lines formed as the flowability of fiber reinforced polymeric material is enhanced .