Gunmetal Grade B.S. 1400: 1985 Nominal Composition 2% PS N/mm Min Tensile Strength N/mm Min Elongation % Min Brinell Hardness Min G1/BC3 88/10/2 245 15 G1/BC2 88/8/4 245 20 LG1 88/3/9/5 85 180 15 60 LG2 85/5/5/5 90 200 13 60 LG3 86/7/5/2 LG4 88/7/2/3 130 230 14 65 BC1 82/3/10/5 165 15 BC6 85/5/5/5 215 18