A permanent magnet suitable for use in a wire print head is formed of plural split segments. Each split segment is formed by compressing metal powder in a punching direction in the presence of a magnetic field that is perpendicular to the punching direction. The split segments are combined together into...http://www.google.ca/patents/US5232295?utm_source=gb-gplus-sharePatent US5232295 - Wire print head and process for fabricating it
