Bl This standard refers to iron and manganese alloys that are used as deoxidizers and fuels in the manufacture of steel or to increase the proportion of manganese in steel and in special ferrous foundries. B-2 This standard also refers to ferromanganese that is used as an alloy or as a deoxidizer in non-ferrous metals. B-3 In this standard, four types of ferromanganese are considered: type I, high carbon content, type II, medium carbon content, type III, low carbon content, type IV, high manganese content.