Brush Development Company’s main business in 1943 was the production of piezo electric phonograph pickups, the least expensive and most widely used pickup of the late 1930’s. They also, however, produced, in cooperation with Western Electric, the manufacturing division of American Telegraph and Telephone (which had a monopoly of long distance telephone service and a dominant position in local telephone service) magnetic tape sound recorders using hardened steel tape as the recording medium.

Another of their products was wire recorders. These used stainless steel wire, with a composition similar to (or perhaps identical with) high carbon high chromium cutlery steel, which was ferromagnetic, as the recording medium. The recording head was a split ring, with the wire running in a groove in the head, quite similar to the heads used today. High frequency ac bias was used to linearize the recording. The ferritic stainless steel was quite strong. Diamond dies were required to draw it into wire.

The Brush Vice President for Research, Dr.S.J.Begun, obtained a contract from the National Defense Research Council to perform research and development on a substitute for the stainless steel wire. The work was justified by the military use of the recorders and the shortage of facilities for producing the diamond dies. It resulted in the production through work at Battelle Memorial Institute of iron oxide magnetic recording tape of exceptional quality. The Battelle Memorial Institute is a private, not-for-profit applied science and technology deveopment company headquartered in Columbus, Ohio. ...