A sensor for at least detecting steering torque of a steel steering column includes a magnetic field generating element which is configured to generate a magnetic field. The magnetic field penetrates the steering column so as to magnetize a steel material thereof. The sensor also includes a magnetic field detection element which is configured to detect a magnetic field change caused by a magnetoelastic effect of the magnetized steel material of the steering column when the steering column is subjected to torque stress. An output signal of the magnetic field detection element characterizes steering torque. The sensor also includes a base plate bearing the magnetic field generating element and the magnetic field detection element. The base plate is spaced from and separate from the steel steering column. The magnetic field generating element and the magnetic field detection element are directly mounted on the base plate.