Patent ID: 7752922

Claim:
A magnetostrictive torque sensor for detecting a torque, said magnetostrictive torque sensor comprising: an operating shaft adapted to be applied with an external torque; a first hollow shaft and a second hollow shaft that are each individually fixedly press-fitted to the operating shaft, wherein each of the first and second hollow shafts is an annular member which is formed separately and independently from the operating shaft; a first magnetostrictive film formed by plating on an external peripheral surface of the first hollow shaft; and a second magnetostrictive film formed by plating on an external peripheral surface of the second hollow shaft; wherein the first and second magnetostrictive films are heat treated after the first and second hollow shafts having the first and second magnetostrictive films formed thereon have been press-fitted to the operating shaft to induce creep which reduces residual strain created during the press-fitting.