The field of hard materials and hard metals has so far only been addressed in literature in the monograph by Karl Becker and in the form of individual chapters in standard works on powder metallurgy. Due to the rapid developments in this area over the past 20 years, a large portion of the data concerning the known metallic hard materials and hard metals has become outdated. To meet an urgent need in the professional community regarding hard metals and related fields, the authors felt compelled to compile all accessible literature, utilizing their own relevant experiences and publications, into book form. In older literature, metallic hard materials were understood to include only carbides, borides, and nitrides of the transition metals from groups four to six of the periodic table.