Abstract
A torque detection device includes a first yoke and a first magnetic guide member. A first opposing portion of the first magnetic guide member overlaps with a first-yoke ring of the first yoke when the first-yoke ring is projected onto the first opposing portion in an axial direction. Furthermore, the first opposing portion overlaps with an inner surface of a second tubular portion when the inner surface is projected onto the first opposing portion in the axial direction. A housing distance, which is a shortest distance measured from the first opposing portion to the inner surface, is longer than a yoke distance, which is a shortest distance measured from the first opposing portion to the first-yoke ring.