MKM steel

MKM steel, an alloy containing nickel and aluminum, was developed in 1931 by the Japanese metallurgist Tokuhichi Mishima. While conducting research into the properties of nickel, Mishima discovered that a strongly magnetic steel could be created by adding aluminum to non-magnetic nickel steel. 
Characteristics.
The developers claim MKM steel is tough and durable, inexpensive to produce, maintains strong magnetism when miniaturized and can produce a stable magnetic force in spite of temperature changes or vibration. MKM steel is similar to Alnico.
Acronym.
MKM is an acronym for Mitsujima ka magnetic, 'Mitsujima ka' being the name of the inventor's childhood home.