【Composition:】99.95% Graphite, Ash content less than 0.1%. Excellent thermal conductivity and corrosion resistance. Better for Refining than Silicon Carbide Graphite Crucibles. | 【Warm-Tips】Pure graphite crucible can NOT be heating by carbon furnace or charcoal kiln. It will be oxidized and cracked; Pure graphite will start to oxidize at 752 °F （400℃). The withstand temperatures can be 3200 °F if you use Air Electric Furnace. The withstand temperatures can be 5000 °F if you use Vacuum or Gas Protection Furnace. | 【Perfect Performance】Excellent thermal stability for fast heating and cooling; Well corrosion resistance to strong acid and alkali; Good thermal conductivity properties which highly shorten the melting time and save energy; Great impact resistance performance to ensure the reliability of product quality. | 【Application】Used for melting and casting metals such as Gold, Silver, Brass, Aluminum, Copper, Zinc, Plumbum, etc; 665g Gold / 320g Silver; Inner 2.56x 1.18 x 0.78 inch (1.18 fl oz). | 【Package & Service 】1x Graphite Casting Melting Ingot; We offer 30 days free returns, 90 days warranty; Any questions please feel free to contact us.