The tie rod is part of the steering mechanism in a vehicle. A tie rod is a slender structural rod that is used as a tie and capable of carrying tensile loads only. A tie rod consists of an inner and an outer end. The spokes on a bicycle's wheels are tie rods. As the ratio of its length to the radius of gyration of its cross section is normally quite large, it would likely buckle under the action of compressive forces.

The tie rod transmits force from the steering center link or the rack gear to the steering knuckle. This will cause the wheel to turn. The outer tie rod end connects with an adjusting sleeve, which allows the length of the tie rod to be adjustable. This adjustment is used to set a vehicle's alignment angle.