The leaded gunmetal test bars (JIS BC 6 and 7) cast in dry sand, green sand and shell molds have superior mechanical properties over the JIS limitations. The nature of mechanical properties of the alloys is similar to that in the tin bronzes. In the stepped casting and L-type castig the thickness and feeding direction have marked influences on the properties. Heavy sections have lowered mechanical properties and up-run is more favourable than down-run. The relation between the tensile strength and the elongation is plotted from all the tensile data.
