Untempered martensite is low in toughness and therefore brittle. Some brands of couverture chocolate are packaged tempered, and others are packaged untempered. It is not possible to autogenous weld HY-80 due to the formation of untempered martensite. Untempered martensitic steel, while very hard, is too brittle to be useful for most applications. The "meh" is an untempered instrument, and its specific intonation varies by region. Cole is the founder and leader of the Untempered Ensemble.