A data storage device for recording to and reading from magnetic thread includes a head assembly having an opening through which the magnetic thread passes. Transducing elements are positioned around the inner surface of the opening and interact with longitudinally-extending parallel tracks formatted around the surface of the magnetic thread. If the number of tracks is greater than the number of transducing elements, the transducing elements may be rotatable about the magnetic thread to position the transducing elements to interact with other tracks. The head assembly may open to aid positioning the magnetic thread within the opening in the head assembly during loading. If desired, multiple head assemblies may be placed in the thread path to improve data throughput. The magnetic thread may be formed with a non-circular cross-section and the opening in the head assembly may have a corresponding cross-section to reduce twisting of the magnetic thread as it passes through the opening.