The Alnico material (composed predominantly of aluminum, nickel, and cobalt with minor amounts of other elements including titanium and copper) is manufactured through either a Casting or Sintering process. Compared to modern materials alnico has a low coercivity. The main advantage of alnico is the very low temperature coefficient and the wide temperature range from -273 °C to more than + 400 °C for practical use.
Alnico is very hard and brittle. Machining or drilling cannot therefore be accomplished by ordinary methods. Holes are usually cored in at the foundry. Magnets are cast or sintered as closely as possible to required size so that abrasive grinding to finish dimensions and tolerances is minimized.