Retentivity
The ability of a material to hold its magnetism after the magnetizing field has been removed.
Also defined in 1 more source
The ability of a magnetizable material to retain the alignment of the magnetic domains after the magnetizing force has been removed. Hard steel normally has a high retentivity, while soft iron and electrical steel both have very low retentivity.
Aviation Maintenance Technician Handbook — Powerplant, p. G-23