An electrical connector includes a machined metal contact housing having a contact housing cavity surrounded by a contact housing wall. Two or more electrical contacts are disposed within the contact housing cavity. A polarization alignment key is disposed on an inside surface of the contact housing wall. A key-retaining pocket on the contact housing intersects an inside surface of the contact housing wall to form a longitudinal slot opening between the key-retaining pocket and the contact housing cavity. The key is mounted on the contact housing by virtue of a portion thereof being disposed in the key-retaining pocket. The electrical connector may be manufactured by (1) machining the key-retaining pocket in a metal blank from which the contact housing will be formed, (2) machining the contact housing cavity in the blank so as to intersect the key-retaining pocket, (3) mounting the key, and (4) mounting the electrical contacts.