BRUSH CASTING ALLOYS 245C AND 245CT are beryllium copper (2.25-2.55% Be) alloys of high strength with cobalt as the second alloying element (0.35-0.70% Co). Use is in the age-hardened temper. Brush casting alloy 245CT is the fine-grained version. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, and machining. Filing Code: Cu-577. Producer or source: Brush Wellman Inc..