The invention of artificial magnetization method played a huge role in the application and development of the compass. It is also a major event in the development history of magnetism and geomagnetism.

Shen Kuo of the Northern Song Dynasty mentioned another method of artificial magnetization in his "Mengxi Bi Tan": "The Fang family used magnets to rub the needle tip, which can guide." According to Shen Kuo, technicians at that time used magnets to rub the sewing needle, which can make the needle magnetic. From a current perspective, this is a method of utilizing the magnetic field of natural magnets to make the arrangement of magnetic domains inside the steel needle tend towards a certain direction, thereby making the steel needle show magnetism. This method is simpler than geomagnetic method, and the magnetization effect is better than geomagnetic method. The invention of friction method is not only the earliest in the world, but also creates conditions for the emergence of practical magnetic directional devices.

Shen Kuo also talked about various phenomena that occur when using friction magnetization in his supplementary remarks on "Mengxi Bi Tan": "When using a magnet to rub a needle, the sharp point is often pointed out, and there are also those who point north, and the fear of stones is not... The opposite is true for the north and south, and there should be differences, which have not been deeply studied." This means that after using a magnet to rub a sewing needle, the needle sometimes points out, and sometimes points north. From a current perspective, magnets have two poles, N and S. When magnetized, the orientation of the needle tip of the sewing needle is different, and the direction after magnetization is also different. But Shen Kuo did not know this truth. He truthfully recorded this phenomenon and admitted that he did not think deeply. In the hope that future generations can further explore