Discover professional-grade metal refining with PRESIDENTGOLD's #14 4-3/8" Mabor Magnesia Tapered Cupel Sets. These precision-engineered cupels are specifically designed for gold and silver assaying, featuring superior heat resistance and durability thanks to their high-quality magnesia construction. The tapered design optimizes the absorption of impurities during the refining process, helping you achieve exceptionally pure results. Each cupel in the set works through precise oxidation to produce clean gold or silver beads. Whether you're a professional jeweler, metalworker, or precious metal refiner, these cupels provide the reliability and consistency needed for accurate assaying. The 4-3/8" size offers ample capacity for standard refining operations, while the robust construction ensures consistent performance throughout the process. Perfect for both commercial and artisanal refining operations, these cupels are an essential tool for anyone serious about precious metal work.