BELMONT ALLOY 2431 is a bismuth-base alloy that can be melted easily. This non-eutectic alloy melts through the temperature range 160-190 F. It was originally developed as an ingot alloy and sold in a kit to be used by children for casting soldiers and other small objects. It has the unique properties of shrinking immediately upon solidification and growing back to zero in one hour, followed by additional growth. This shrinkage-growth makes it an ideal alloy for proof casting and precision measurement of internal dimensions. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on casting, forming, heat treating, and machining. Filing Code: Bi-12. Producer or source: Belmont Metals Inc..