a torsion bar, and force is applied to the bar via a lever on each end

A wooden bar attached to the fuchells (q.v.) and bearing under the bottom of the perch (q.v.) to strengthen the forecarriage gear when turning on the king pin (q.v.).

a spring, and as such should be made of spring steel, or some form of hardened steel

a steel rod that goes from strut knuckle to strut knuckle across the car