The present invention relates to the technical field of magnetic attraction lines, and in particular, to a magnetic attraction line convenient to store, including a line body and a connector, where line cores are connected into the line body, outer surfaces of the line cores are covered with an injection molding layer, an outer surface of the injection molding layer is coated with a magnetic attraction layer, an outer surface of the magnetic attraction layer is coated with a protection layer, and an isolation and protection layer is disposed between the magnetic attraction layer and the injection molding layer. Through a coating connection between the magnetic attraction layer and the injection molding layer, and under the action of the magnetic attraction layer, a magnetic attraction connection effect of the line bodies is achieved, and then a magnetic storage effect of the line bodies is achieved.

A magnetic data cable is disclosed, including cable body and a data interface connected to both ends of the cable body. The cable body includes a cored wire group and an external protective layer wrapped outside of the cored wire group, a flexible magnetic strip is provided in the outer protective layer, and the flexible magnetic strip is located alongside of the cored wire group and extends parallel to the cored wire group. It is convenient to adjust diameter of the coil after the data cable has been coiled so as to facilitate storing of the data cable, and it is easy to operate.

The invention discloses an R-T-B-based permanent magnet, and preparation method therefor and use thereof. The R-T-B-based permanent magnet comprises a nitrogen content of X ppm which satisfies 500X1300, the R-T-B-based permanent magnet has an average grain size of D m which satisfies 2.6lnX+20D2.3lnX+19.6; the R-T-B-based permanent magnet comprises a main phase grain and a grain boundary phase; the main phase grain comprise R.sub.2Fe.sub.14B; the grain boundary phases is distributed between main phase grains; and the grain boundary phase comprises a RN enriched area having a volume fraction of less than 10% in the grain boundary phase. In the R-T-B-based permanent magnet of the present invention, nitrogen elements are uniformly distributed at the grain boundaries, and no NdN agglomerates are formed or the content thereof is extremely low, thereby increasing the coercive force Hcj of the magnet, reducing the magnetic loss at high-temperature, and improving the corrosion resistance.