"NSN USED TO PURCHASE A MINIMUM OF 160 CONTAINERS AND UP;CERTIFICATION GE B50TF190 CLASS A;RC 46 HARDNESS;6000 PSI MINIMUM STRENGTH;MACHINES READILY WITH SILICON-CARBIDE TOOLS.HAS LOWER CHROMIUM AND HIGHER SILICON CONTENT,BETTER SUITED TO WITHSTAND HOSTILE OXIDATION AND HOT CORROSION ENVIRONMENTS UP UP TO 1750DEG (F)"