Nihonweld NHF-ST6R description: NHF ST-6R Bare rod produce a medium hardness cobalt-chromium deposit for high temperature applications with good abrasive wear and good impact resistance. NHF ST-6R is the most versatile and widely used cobalt alloy with a good balance of abrasion and impact resistance. Chromium carbides contained in the deposit, have excellent resistance to many forms of chemical and mechanical degradation, including galling and cavitation erosion. It bonds well with all weldable steels, including stainless.