Features: The graphite crucible has good thermal stability, suitable for emergency heat or cold usage condition. Good corrosion resistance and impact resistance. Excellent acids resistance and alkalis resistance. The graphite crucible has good thermal conductivity properties,it can greatly shorten the melting time and saved energy. The ashes of graphite crucible is less than 0.1%,to ensure that the precious metal in the smelting is not contaminated. It can melt gold, silver, platinum and other precious metals and other alloys,with long service life. you can select the size you need, and the size you can find on the listing photo for gold and silver melting after the formation of gold and silver pieces can also be used as graphite crucible melting into non-ferrous metals, test analysis, as the ingot mold and other purposes Specification: Material: Graphite Type:(optional) 30g# 40g# 50g# 100g# 200g# 300g# 500g# Size: 30g Gold# Outside 241614 mm/10.60.6inch Inside 181010mm/0.70.40.4inch 40g Gold# Outside 252412 mm/110.57inch Inside 20187mm/0.80.70.3inch 50g Gold# Outside 302412 mm/1.210.57inch Inside 24188mm/10.70.3inch 100g Gold# Outside 553720 mm/2.21.50.8inch Inside 451410mm/1.870.60.4inch 200g Gold# Outside 605020mm/2.420.8inch Inside 453510mm/1.871.40.8inch 300g Gold# Outside 705720 mm/2.82.20.8inch Inside 503710mm/21.50.8inch 500g Gold# Outside 706726 mm/2.82.61inch Inside 504716mm/21.90.63inch Quantity: 1 PC Note: Size for manual measurement, there may be a 0 to 2 cm error, belongs to the normal phenomenon. And due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Contents: 1 PC x Graphite Melting Crucible