BRUSH WELLMAN I-70A is an instrument and optical grade of beryllium strengthened by a dispersion of 0.7% beryllium oxide maximum. It has relatively low strength and fairly low ductility (a minimum of 2% elongation). Its uses include optical applications, instrumentation, and optical-instrumentation applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: Be-6. Producer or source: Brush Wellman Inc..