Silicone Bronze Casting Grain, PolishedFabricated from high quality primary metal sources, each batch of Everdure is guaranteed to be consistent in fluidity, ductility, hardness, color and solidification. Bronze S copper casting grain is a lighter colored alloy with excellent tight grain solidification traits. Considered a silicon bronze, polished for consistent results. Each grain ranges from 1 2" in diameter and below. Available by the pound, and made in USA 95% Copper (Cu) 4% Silicon