Abstract: A method of constructing a magnetic flux gap comprising fabricating a first portion from a material having low reluctance and so as to provide an end surface, and a cylindrical inner surface having a diameter, fabricating a second portion from a material having high reluctance and so as to provide axially spaced first and second end surfaces, and a cylindrical inner surface having a diameter greater than the diameter of said cylindrical inner surface of said first portion, fabricating a third portion from a material having low reluctance and so as to provide an end surface, and a cylindrical inner surface having a diameter substantially equal to the diameter of said cylindrical inner surface of said first portion, fixing together the first and second portions with the first end surface of the second portion in axially abutting adjacent relation to the end surface of the first portion and with said cylindrical inner surfaces in concentric relation, fixing together the second and third portions with the second

Abstract: A monolithic metallic drive shaft for a marine propulsion device is disclosed which is resistant to corrosion. The drive shaft comprises proximal and distal end portions, each of which has a predetermined surface hardness. The surface hardness of one of the proximal and distal end portions is greater than the surface hardness of the other of the proximal and distal end portions.