Alnicos ;are a group of heat-treated Fe–Co–Ni–Al–Cu alloys that can be divided into two main subgroups: isotropic alloys containing 0–20 wt.% Co (alnicos 1–4) and anisotropic alloys with 22–24 wt.% Co and titanium content of 5–8 wt.% (alnicos 5–9). The anisotropy in the case of alnicos 5–9 is produced by controlled cooling or isothermal heat treatment in a saturating magnetic field. http://www.sensmagnetics.com/alnico-1