KS steel

KS Steel, a permanent magnetic steel with three times the magnetic resistance of tungsten steel, was developed in 1917 by the Japanese scientist and inventor Kotaro Honda. KS stands for Kichizaemon Sumitomo, the head of the family-run conglomerate, who provided financial support for the research leading to KS Steel's invention. Honda would go on to invent NKS steel in 1933 whose magnetic resistance is several times higher than that of KS Steel.

...
Wikipedia